diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnnotationIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnnotationIndex.java
index f3055fc59b42..fbf4508682b3 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnnotationIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnnotationIndex.java
@@ -36,6 +36,7 @@ public class JavaAnnotationIndex extends StringStubIndexExtension<PsiAnnotation>
     return ourInstance;
   }
 
+  @NotNull
   @Override
   public StubIndexKey<String, PsiAnnotation> getKey() {
     return JavaStubIndexKeys.ANNOTATIONS;
diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnonymousClassBaseRefOccurenceIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnonymousClassBaseRefOccurenceIndex.java
index c84dc8716520..2521522325c9 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnonymousClassBaseRefOccurenceIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaAnonymousClassBaseRefOccurenceIndex.java
@@ -37,6 +37,7 @@ public class JavaAnonymousClassBaseRefOccurenceIndex extends StringStubIndexExte
   }
 
 
+  @NotNull
   @Override
   public StubIndexKey<String, PsiAnonymousClass> getKey() {
     return JavaStubIndexKeys.ANONYMOUS_BASEREF;
diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFieldNameIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFieldNameIndex.java
index 6d45c799f195..54eb0edf6a05 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFieldNameIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFieldNameIndex.java
@@ -36,6 +36,7 @@ public class JavaFieldNameIndex extends StringStubIndexExtension<PsiField> {
     return ourInstance;
   }
 
+  @NotNull
   @Override
   public StubIndexKey<String, PsiField> getKey() {
     return JavaStubIndexKeys.FIELDS;
diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFullClassNameIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFullClassNameIndex.java
index 6bebd462dd16..40c75f3551b3 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFullClassNameIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaFullClassNameIndex.java
@@ -36,6 +36,7 @@ public class JavaFullClassNameIndex extends IntStubIndexExtension<PsiClass> {
     return ourInstance;
   }
 
+  @NotNull
   @Override
   public StubIndexKey<Integer, PsiClass> getKey() {
     return JavaStubIndexKeys.CLASS_FQN;
diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaMethodNameIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaMethodNameIndex.java
index 04e9732ebb41..a92856f2564c 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaMethodNameIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaMethodNameIndex.java
@@ -36,6 +36,7 @@ public class JavaMethodNameIndex extends StringStubIndexExtension<PsiMethod> {
     return ourInstance;
   }
 
+  @NotNull
   @Override
   public StubIndexKey<String, PsiMethod> getKey() {
     return JavaStubIndexKeys.METHODS;
diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaShortClassNameIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaShortClassNameIndex.java
index 6d3613b8e29e..c2c49d71cdec 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaShortClassNameIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaShortClassNameIndex.java
@@ -36,6 +36,7 @@ public class JavaShortClassNameIndex extends StringStubIndexExtension<PsiClass>
     return ourInstance;
   }
 
+  @NotNull
   @Override
   public StubIndexKey<String, PsiClass> getKey() {
     return JavaStubIndexKeys.CLASS_SHORT_NAMES;
diff --git a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaSuperClassNameOccurenceIndex.java b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaSuperClassNameOccurenceIndex.java
index 65591b359c6c..a70b7ea700d4 100644
--- a/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaSuperClassNameOccurenceIndex.java
+++ b/java/java-impl/src/com/intellij/psi/impl/java/stubs/index/JavaSuperClassNameOccurenceIndex.java
@@ -37,6 +37,7 @@ public class JavaSuperClassNameOccurenceIndex extends StringStubIndexExtension<P
     return ourInstance;
   }
 
+  @NotNull
   @Override
   public StubIndexKey<String, PsiReferenceList> getKey() {
     return JavaStubIndexKeys.SUPER_CLASSES;
diff --git a/platform/lang-api/src/com/intellij/psi/stubs/IntStubIndexExtension.java b/platform/lang-api/src/com/intellij/psi/stubs/IntStubIndexExtension.java
index e0b076115cd4..083154c437ff 100644
--- a/platform/lang-api/src/com/intellij/psi/stubs/IntStubIndexExtension.java
+++ b/platform/lang-api/src/com/intellij/psi/stubs/IntStubIndexExtension.java
@@ -22,12 +22,14 @@ package com.intellij.psi.stubs;
 import com.intellij.psi.PsiElement;
 import com.intellij.util.io.EnumeratorIntegerDescriptor;
 import com.intellij.util.io.KeyDescriptor;
+import org.jetbrains.annotations.NotNull;
 
 public abstract class IntStubIndexExtension<Psi extends PsiElement> extends AbstractStubIndex<Integer, Psi> {
   public int getVersion() {
     return 1;
   }
 
+  @NotNull
   public KeyDescriptor<Integer> getKeyDescriptor() {
     return EnumeratorIntegerDescriptor.INSTANCE;
   }
diff --git a/platform/lang-api/src/com/intellij/psi/stubs/StringStubIndexExtension.java b/platform/lang-api/src/com/intellij/psi/stubs/StringStubIndexExtension.java
index b4ddde4668db..4d17ab028629 100644
--- a/platform/lang-api/src/com/intellij/psi/stubs/StringStubIndexExtension.java
+++ b/platform/lang-api/src/com/intellij/psi/stubs/StringStubIndexExtension.java
@@ -22,12 +22,14 @@ package com.intellij.psi.stubs;
 import com.intellij.psi.PsiElement;
 import com.intellij.util.io.EnumeratorStringDescriptor;
 import com.intellij.util.io.KeyDescriptor;
+import org.jetbrains.annotations.NotNull;
 
 public abstract class StringStubIndexExtension<Psi extends PsiElement> extends AbstractStubIndex<String, Psi> {
   public int getVersion() {
     return 2;
   }
 
+  @NotNull
   public KeyDescriptor<String> getKeyDescriptor() {
     return new EnumeratorStringDescriptor();
   }
diff --git a/platform/lang-api/src/com/intellij/psi/stubs/StubIndexExtension.java b/platform/lang-api/src/com/intellij/psi/stubs/StubIndexExtension.java
index 5255abf93b4a..8ee1c2dbc253 100644
--- a/platform/lang-api/src/com/intellij/psi/stubs/StubIndexExtension.java
+++ b/platform/lang-api/src/com/intellij/psi/stubs/StubIndexExtension.java
@@ -22,11 +22,16 @@ package com.intellij.psi.stubs;
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.psi.PsiElement;
 import com.intellij.util.io.KeyDescriptor;
+import org.jetbrains.annotations.NotNull;
 
 public interface StubIndexExtension<Key, Psi extends PsiElement> {
   ExtensionPointName<StubIndexExtension> EP_NAME = ExtensionPointName.create("com.intellij.stubIndex");
 
+  @NotNull
   StubIndexKey<Key, Psi> getKey();
+
   int getVersion();
+
+  @NotNull
   KeyDescriptor<Key> getKeyDescriptor();
 }
\ No newline at end of file
diff --git a/platform/lang-impl/src/com/intellij/util/indexing/MapIndexStorage.java b/platform/lang-impl/src/com/intellij/util/indexing/MapIndexStorage.java
index f8012d9a7628..d0c60582c640 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/MapIndexStorage.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/MapIndexStorage.java
@@ -25,6 +25,7 @@ import com.intellij.util.io.DataExternalizer;
 import com.intellij.util.io.KeyDescriptor;
 import com.intellij.util.io.PersistentMap;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.io.IOException;
@@ -49,8 +50,9 @@ public final class MapIndexStorage<Key, Value> implements IndexStorage<Key, Valu
   private final Lock l = new ReentrantLock();
   private final DataExternalizer<Value> myDataExternalizer;
 
-  public MapIndexStorage(File storageFile, final KeyDescriptor<Key> keyDescriptor,
-                         final DataExternalizer<Value> valueExternalizer,
+  public MapIndexStorage(@NotNull File storageFile,
+                         @NotNull KeyDescriptor<Key> keyDescriptor,
+                         @NotNull DataExternalizer<Value> valueExternalizer,
                          final int cacheSize) throws IOException {
 
     myStorageFile = storageFile;
@@ -67,11 +69,13 @@ public final class MapIndexStorage<Key, Value> implements IndexStorage<Key, Valu
       @NotNull
       public ChangeTrackingValueContainer<Value> createValue(final Key key) {
         return new ChangeTrackingValueContainer<Value>(new ChangeTrackingValueContainer.Initializer<Value>() {
+          @NotNull
           @Override
           public Object getLock() {
             return map.getDataAccessLock();
           }
 
+          @Nullable
           @Override
           public ValueContainer<Value> compute() {
             ValueContainer<Value> value;
@@ -90,7 +94,7 @@ public final class MapIndexStorage<Key, Value> implements IndexStorage<Key, Valu
       }
 
       @Override
-      protected void onDropFromCache(final Key key, final ChangeTrackingValueContainer<Value> valueContainer) {
+      protected void onDropFromCache(final Key key, @NotNull final ChangeTrackingValueContainer<Value> valueContainer) {
         if (valueContainer.isDirty()) {
           try {
             map.put(key, valueContainer);
@@ -192,6 +196,7 @@ public final class MapIndexStorage<Key, Value> implements IndexStorage<Key, Valu
     }
   }
 
+  @NotNull
   @Override
   public Collection<Key> getKeys() throws StorageException {
     List<Key> keys = new ArrayList<Key>();
diff --git a/platform/lang-impl/src/com/intellij/util/indexing/ValueContainerMap.java b/platform/lang-impl/src/com/intellij/util/indexing/ValueContainerMap.java
index 9c964a820974..cb26b39d4994 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/ValueContainerMap.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/ValueContainerMap.java
@@ -4,6 +4,7 @@ import com.intellij.openapi.util.io.BufferExposingByteArrayOutputStream;
 import com.intellij.util.io.*;
 import com.intellij.util.io.DataOutputStream;
 import gnu.trove.TIntHashSet;
+import org.jetbrains.annotations.NotNull;
 
 import java.io.*;
 import java.util.Iterator;
@@ -13,17 +14,17 @@ import java.util.Iterator;
  *         Date: 8/10/11
  */
 class ValueContainerMap<Key, Value> extends PersistentHashMap<Key, ValueContainer<Value>> {
+  @NotNull private final ValueContainerExternalizer<Value> myValueContainerExternalizer;
 
-  private final ValueContainerExternalizer<Value> myValueContainerExternalizer;
-
-  ValueContainerMap(final File file,
-                           KeyDescriptor<Key> keyKeyDescriptor,
-                           DataExternalizer<Value> valueExternalizer) throws IOException {
+  ValueContainerMap(@NotNull final File file,
+                    @NotNull KeyDescriptor<Key> keyKeyDescriptor,
+                    @NotNull DataExternalizer<Value> valueExternalizer) throws IOException {
 
     super(file, keyKeyDescriptor, new ValueContainerExternalizer<Value>(valueExternalizer));
     myValueContainerExternalizer = (ValueContainerExternalizer<Value>)myValueExternalizer;
   }
 
+  @NotNull
   Object getDataAccessLock() {
     return myEnumerator;
   }
@@ -54,7 +55,7 @@ class ValueContainerMap<Key, Value> extends PersistentHashMap<Key, ValueContaine
 
         appendData(key, new PersistentHashMap.ValueDataAppender() {
           @Override
-          public void append(final DataOutput out) throws IOException {
+          public void append(@NotNull final DataOutput out) throws IOException {
             out.write(bytes.getInternalBuffer(), 0, bytes.size());
           }
         });
@@ -67,18 +68,18 @@ class ValueContainerMap<Key, Value> extends PersistentHashMap<Key, ValueContaine
   }
 
   private static final class ValueContainerExternalizer<T> implements DataExternalizer<ValueContainer<T>> {
-    private final DataExternalizer<T> myExternalizer;
+    @NotNull private final DataExternalizer<T> myExternalizer;
 
-    private ValueContainerExternalizer(DataExternalizer<T> externalizer) {
+    private ValueContainerExternalizer(@NotNull DataExternalizer<T> externalizer) {
       myExternalizer = externalizer;
     }
 
     @Override
-    public void save(final DataOutput out, final ValueContainer<T> container) throws IOException {
+    public void save(final DataOutput out, @NotNull final ValueContainer<T> container) throws IOException {
       saveImpl(out, container, false);
     }
 
-    public void saveAsRemoved(final DataOutput out, final ValueContainer<T> container) throws IOException {
+    public void saveAsRemoved(final DataOutput out, @NotNull final ValueContainer<T> container) throws IOException {
       saveImpl(out, container, true);
     }
 
@@ -86,7 +87,7 @@ class ValueContainerMap<Key, Value> extends PersistentHashMap<Key, ValueContaine
       DataInputOutputUtil.writeSINT(out, -inputId);
     }
 
-    private void saveImpl(final DataOutput out, final ValueContainer<T> container, final boolean asRemovedData) throws IOException {
+    private void saveImpl(final DataOutput out, @NotNull final ValueContainer<T> container, final boolean asRemovedData) throws IOException {
       DataInputOutputUtil.writeSINT(out, container.size());
       for (final Iterator<T> valueIterator = container.getValueIterator(); valueIterator.hasNext();) {
         final T value = valueIterator.next();
@@ -106,6 +107,7 @@ class ValueContainerMap<Key, Value> extends PersistentHashMap<Key, ValueContaine
       }
     }
 
+    @NotNull
     @Override
     public ValueContainerImpl<T> read(final DataInput in) throws IOException {
       DataInputStream stream = (DataInputStream)in;
diff --git a/platform/util/src/com/intellij/util/io/PersistentBTreeEnumerator.java b/platform/util/src/com/intellij/util/io/PersistentBTreeEnumerator.java
index 67dedfb5348b..b15c75d8278a 100644
--- a/platform/util/src/com/intellij/util/io/PersistentBTreeEnumerator.java
+++ b/platform/util/src/com/intellij/util/io/PersistentBTreeEnumerator.java
@@ -65,10 +65,10 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
   private static final int DIRTY_MAGIC = 0xbabe1977;
   private static final int VERSION = 6 + IntToIntBtree.VERSION;
   private static final int CORRECTLY_CLOSED_MAGIC = 0xebabafc + VERSION + PAGE_SIZE;
-  private static Version ourVersion = new Version(CORRECTLY_CLOSED_MAGIC, DIRTY_MAGIC);
+  @NotNull private static Version ourVersion = new Version(CORRECTLY_CLOSED_MAGIC, DIRTY_MAGIC);
   private static final int KEY_SHIFT = 1;
 
-  public PersistentBTreeEnumerator(File file, KeyDescriptor<Data> dataDescriptor, int initialSize) throws IOException {
+  public PersistentBTreeEnumerator(@NotNull File file, @NotNull KeyDescriptor<Data> dataDescriptor, int initialSize) throws IOException {
     super(file, new ResizeableMappedFile(file, initialSize, ourLock, VALUE_PAGE_SIZE, true), dataDescriptor, initialSize,
           ourVersion, new RecordBufferHandler(), false);
 
@@ -84,7 +84,8 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
     }
   }
 
-  private File indexFile(File file) {
+  @NotNull
+  private File indexFile(@NotNull File file) {
     return new File(file.getPath() + "_i");
   }
 
@@ -157,7 +158,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
     return pageStart;
   }
 
-  public boolean processAllDataObject(final Processor<Data> processor, @Nullable final DataFilter filter) throws IOException {
+  public boolean processAllDataObject(@NotNull final Processor<Data> processor, @Nullable final DataFilter filter) throws IOException {
     if(myInlineKeysNoMapping) {
       return traverseAllRecords(new RecordsProcessor() {
         public boolean process(final int record) throws IOException {
@@ -173,7 +174,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
   }
 
   @Override
-  public boolean traverseAllRecords(RecordsProcessor p) throws IOException {
+  public boolean traverseAllRecords(@NotNull RecordsProcessor p) throws IOException {
     try {
       synchronized (ourLock) {
 
@@ -183,7 +184,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
         collectLeafPages(btree.root, leafPages);
         Collections.sort(leafPages, new Comparator<IntToIntBtree.BtreeIndexNodeView>() {
           @Override
-          public int compare(IntToIntBtree.BtreeIndexNodeView o1, IntToIntBtree.BtreeIndexNodeView o2) {
+          public int compare(@NotNull IntToIntBtree.BtreeIndexNodeView o1, @NotNull IntToIntBtree.BtreeIndexNodeView o2) {
             return o1.address - o2.address;
           }
         });
@@ -218,7 +219,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
     }
   }
 
-  private void collectLeafPages(IntToIntBtree.BtreeIndexNodeView node, List<IntToIntBtree.BtreeIndexNodeView> leafPages) {
+  private void collectLeafPages(@NotNull IntToIntBtree.BtreeIndexNodeView node, @NotNull List<IntToIntBtree.BtreeIndexNodeView> leafPages) {
     if (node.isIndexLeaf()) {
       leafPages.add(node);
       return;
@@ -259,7 +260,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
   }
 
   @Override
-  public void setRecordHandler(PersistentEnumeratorBase.RecordBufferHandler<PersistentEnumeratorBase> recordHandler) {
+  public void setRecordHandler(@NotNull PersistentEnumeratorBase.RecordBufferHandler<PersistentEnumeratorBase> recordHandler) {
     myExternalKeysNoMapping = false;
     super.setRecordHandler(recordHandler);
   }
@@ -422,7 +423,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
     private byte[] myBuffer;
 
     @Override
-    int recordWriteOffset(PersistentBTreeEnumerator enumerator, byte[] buf) {
+    int recordWriteOffset(@NotNull PersistentBTreeEnumerator enumerator, @NotNull byte[] buf) {
       if (enumerator.myFirstPageStart == -1) {
         enumerator.myFirstPageStart = enumerator.myDataPageStart = enumerator.allocPage();
       }
@@ -442,7 +443,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
 
     @NotNull
     @Override
-    byte[] getRecordBuffer(PersistentBTreeEnumerator enumerator) {
+    byte[] getRecordBuffer(@NotNull PersistentBTreeEnumerator enumerator) {
       if (myBuffer == null) {
         myBuffer = new byte[enumerator.myInlineKeysNoMapping ? 0:RECORD_SIZE];
       }
@@ -450,7 +451,7 @@ public class PersistentBTreeEnumerator<Data> extends PersistentEnumeratorBase<Da
     }
 
     @Override
-    void setupRecord(PersistentBTreeEnumerator enumerator, int hashCode, int dataOffset, byte[] buf) {
+    void setupRecord(@NotNull PersistentBTreeEnumerator enumerator, int hashCode, int dataOffset, byte[] buf) {
       if (!enumerator.myInlineKeysNoMapping) Bits.putInt(buf, 0, dataOffset);
     }
   }
diff --git a/platform/util/src/com/intellij/util/io/PersistentEnumerator.java b/platform/util/src/com/intellij/util/io/PersistentEnumerator.java
index c159771a027c..2c71eab96dd2 100644
--- a/platform/util/src/com/intellij/util/io/PersistentEnumerator.java
+++ b/platform/util/src/com/intellij/util/io/PersistentEnumerator.java
@@ -48,7 +48,7 @@ public class PersistentEnumerator<Data> extends PersistentEnumeratorBase<Data> {
   private int valuesCount; // TODO: valuesCount should be persistent
   private static final Version ourVersion = new Version(CORRECTLY_CLOSED_MAGIC, DIRTY_MAGIC);
 
-  public PersistentEnumerator(File file, KeyDescriptor<Data> dataDescriptor, int initialSize) throws IOException {
+  public PersistentEnumerator(@NotNull File file, @NotNull KeyDescriptor<Data> dataDescriptor, int initialSize) throws IOException {
     super(file, new ResizeableMappedFile(file, initialSize, ourLock), dataDescriptor, initialSize, ourVersion,
           new RecordBufferHandler(), true);
   }
@@ -57,11 +57,11 @@ public class PersistentEnumerator<Data> extends PersistentEnumeratorBase<Data> {
     allocVector(FIRST_VECTOR);
   }
 
-  public synchronized boolean traverseAllRecords(RecordsProcessor p) throws IOException {
+  public synchronized boolean traverseAllRecords(@NotNull RecordsProcessor p) throws IOException {
     return traverseRecords(FIRST_VECTOR_OFFSET, SLOTS_PER_FIRST_VECTOR, p);
   }
 
-  private boolean traverseRecords(int vectorStart, int slotsCount, RecordsProcessor p) throws IOException {
+  private boolean traverseRecords(int vectorStart, int slotsCount, @NotNull RecordsProcessor p) throws IOException {
     synchronized (ourLock) {
       for (int slotIdx = 0; slotIdx < slotsCount; slotIdx++) {
         final int vector = myStorage.getInt(vectorStart + slotIdx * 4);
@@ -186,7 +186,7 @@ public class PersistentEnumerator<Data> extends PersistentEnumeratorBase<Data> {
     return (hashcode >>> (byteN * BITS_PER_LEVEL)) & LEVEL_MASK;
   }
 
-  private int allocVector(final byte[] empty) throws IOException {
+  private int allocVector(@NotNull final byte[] empty) throws IOException {
     final int pos = (int)myStorage.length();
     myStorage.put(pos, empty, 0, empty.length);
     return pos;
@@ -208,7 +208,7 @@ public class PersistentEnumerator<Data> extends PersistentEnumeratorBase<Data> {
   private static class RecordBufferHandler extends PersistentEnumeratorBase.RecordBufferHandler<PersistentEnumerator> {
     private final byte[] myBuffer = new byte[RECORD_SIZE];
 
-    protected int recordWriteOffset(PersistentEnumerator enumerator, byte[] buf) {
+    protected int recordWriteOffset(@NotNull PersistentEnumerator enumerator, byte[] buf) {
       return (int)enumerator.myStorage.length();
     }
 
diff --git a/platform/util/src/com/intellij/util/io/PersistentEnumeratorBase.java b/platform/util/src/com/intellij/util/io/PersistentEnumeratorBase.java
index 613eee243818..596760be09fb 100644
--- a/platform/util/src/com/intellij/util/io/PersistentEnumeratorBase.java
+++ b/platform/util/src/com/intellij/util/io/PersistentEnumeratorBase.java
@@ -73,9 +73,10 @@ abstract class PersistentEnumeratorBase<Data> implements Forceable, Closeable {
     }
   }
   
-  public static abstract class RecordBufferHandler<T extends PersistentEnumeratorBase> {
+  public abstract static class RecordBufferHandler<T extends PersistentEnumeratorBase> {
     abstract int recordWriteOffset(T enumerator, byte[] buf);
-    abstract @NotNull byte[] getRecordBuffer(T enumerator);
+    @NotNull
+    abstract byte[] getRecordBuffer(T enumerator);
     abstract void setupRecord(T enumerator, int hashCode, final int dataOffset, final byte[] buf);
   }
 
@@ -137,8 +138,12 @@ abstract class PersistentEnumeratorBase<Data> implements Forceable, Closeable {
     }
   }
 
-  public PersistentEnumeratorBase(File file, ResizeableMappedFile storage, KeyDescriptor<Data> dataDescriptor, int initialSize,
-                                  Version version, RecordBufferHandler<? extends PersistentEnumeratorBase> recordBufferHandler,
+  public PersistentEnumeratorBase(@NotNull File file,
+                                  @NotNull ResizeableMappedFile storage,
+                                  @NotNull KeyDescriptor<Data> dataDescriptor,
+                                  int initialSize,
+                                  @NotNull Version version,
+                                  @NotNull RecordBufferHandler<? extends PersistentEnumeratorBase> recordBufferHandler,
                                   boolean doCaching) throws IOException {
     myDataDescriptor = dataDescriptor;
     myFile = file;
@@ -210,11 +215,12 @@ abstract class PersistentEnumeratorBase<Data> implements Forceable, Closeable {
 
   protected abstract void setupEmptyFile() throws IOException;
 
+  @NotNull
   public final RecordBufferHandler<PersistentEnumeratorBase> getRecordHandler() {
     return myRecordHandler;
   }
 
-  public void setRecordHandler(RecordBufferHandler<PersistentEnumeratorBase> recordHandler) {
+  public void setRecordHandler(@NotNull RecordBufferHandler<PersistentEnumeratorBase> recordHandler) {
     myRecordHandler = recordHandler;
   }
 
@@ -311,7 +317,7 @@ abstract class PersistentEnumeratorBase<Data> implements Forceable, Closeable {
     return values;
   }
 
-  public static abstract class RecordsProcessor {
+  public abstract static class RecordsProcessor {
     private int myKey;
 
     public abstract boolean process(int record) throws IOException;
diff --git a/platform/util/src/com/intellij/util/io/PersistentEnumeratorDelegate.java b/platform/util/src/com/intellij/util/io/PersistentEnumeratorDelegate.java
index 7dc5f0a802da..34957b1fb0e5 100644
--- a/platform/util/src/com/intellij/util/io/PersistentEnumeratorDelegate.java
+++ b/platform/util/src/com/intellij/util/io/PersistentEnumeratorDelegate.java
@@ -16,6 +16,7 @@
 package com.intellij.util.io;
 
 import com.intellij.openapi.Forceable;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.io.Closeable;
@@ -24,9 +25,9 @@ import java.io.IOException;
 import java.util.Collection;
 
 public class PersistentEnumeratorDelegate<Data> implements Closeable, Forceable {
-  protected final PersistentEnumeratorBase<Data> myEnumerator;
+  @NotNull protected final PersistentEnumeratorBase<Data> myEnumerator;
 
-  public PersistentEnumeratorDelegate(final File file, KeyDescriptor<Data> dataDescriptor, final int initialSize) throws IOException {
+  public PersistentEnumeratorDelegate(@NotNull final File file, @NotNull KeyDescriptor<Data> dataDescriptor, final int initialSize) throws IOException {
     myEnumerator = useBtree() ? new PersistentBTreeEnumerator<Data>(file, dataDescriptor, initialSize) :
                    new PersistentEnumerator<Data>(file, dataDescriptor, initialSize);
   }
diff --git a/platform/util/src/com/intellij/util/io/PersistentHashMap.java b/platform/util/src/com/intellij/util/io/PersistentHashMap.java
index 297b733d7541..592c566e3573 100644
--- a/platform/util/src/com/intellij/util/io/PersistentHashMap.java
+++ b/platform/util/src/com/intellij/util/io/PersistentHashMap.java
@@ -57,8 +57,8 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
   private static final long USED_LONG_VALUE_MASK = 1L << 62;
   private static final int POSITIVE_VALUE_SHIFT = 1;
   private final int myParentValueRefOffset;
-  private final byte[] myRecordBuffer;
-  private final byte[] mySmallRecordBuffer;
+  @NotNull private final byte[] myRecordBuffer;
+  @NotNull private final byte[] mySmallRecordBuffer;
   private final boolean myCanReEnumerate;
   private int myWatermarkId;
   private boolean myIntAddressForNewRecord;
@@ -73,17 +73,19 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
       ((UnsyncByteArrayOutputStream)out).reset();
     }
     
+    @NotNull
     private BufferExposingByteArrayOutputStream getInternalBuffer() {
       return (BufferExposingByteArrayOutputStream)out;      
     }
   }
 
   private final LimitedPool<AppendStream> myStreamPool = new LimitedPool<AppendStream>(10, new LimitedPool.ObjectFactory<AppendStream>() {
+    @NotNull
     public AppendStream create() {
       return new AppendStream();
     }
 
-    public void cleanup(final AppendStream appendStream) {
+    public void cleanup(@NotNull final AppendStream appendStream) {
       appendStream.reset();
     }
   });  
@@ -94,7 +96,7 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
       return myStreamPool.alloc();
     }
 
-    protected void onDropFromCache(final Key key, final AppendStream value) {
+    protected void onDropFromCache(final Key key, @NotNull final AppendStream value) {
       synchronized (PersistentEnumerator.ourLock) {
         try {
           final BufferExposingByteArrayOutputStream bytes = value.getInternalBuffer();
@@ -128,11 +130,11 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
     }
   });
 
-  public PersistentHashMap(final File file, KeyDescriptor<Key> keyDescriptor, DataExternalizer<Value> valueExternalizer) throws IOException {
+  public PersistentHashMap(@NotNull final File file, @NotNull KeyDescriptor<Key> keyDescriptor, @NotNull DataExternalizer<Value> valueExternalizer) throws IOException {
     this(file, keyDescriptor, valueExternalizer, INITIAL_INDEX_SIZE);
   }
   
-  public PersistentHashMap(final File file, KeyDescriptor<Key> keyDescriptor, DataExternalizer<Value> valueExternalizer, final int initialSize) throws IOException {
+  public PersistentHashMap(@NotNull final File file, @NotNull KeyDescriptor<Key> keyDescriptor, @NotNull DataExternalizer<Value> valueExternalizer, final int initialSize) throws IOException {
     super(checkDataFiles(file), keyDescriptor, initialSize);
 
     final PersistentEnumeratorBase.RecordBufferHandler<PersistentEnumeratorBase> recordHandler = myEnumerator.getRecordHandler();
@@ -153,7 +155,7 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
       }
 
       @Override
-      void setupRecord(PersistentEnumeratorBase enumerator, int hashCode, int dataOffset, byte[] buf) {
+      void setupRecord(PersistentEnumeratorBase enumerator, int hashCode, int dataOffset, @NotNull byte[] buf) {
         recordHandler.setupRecord(enumerator, hashCode, dataOffset, buf);
         for (int i = myParentValueRefOffset; i < buf.length; i++) {
           buf[i] = 0;
@@ -217,17 +219,18 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
     return false;
   }
 
-  private static File checkDataFiles(final File file) {
+  @NotNull
+  private static File checkDataFiles(@NotNull final File file) {
     if (!file.exists()) {
       deleteFilesStartingWith(getDataFile(file));
     }
     return file;
   }
 
-  public static void deleteFilesStartingWith(File prefixFile) {
+  public static void deleteFilesStartingWith(@NotNull File prefixFile) {
     final String baseName = prefixFile.getName();
     final File[] files = prefixFile.getParentFile().listFiles(new FileFilter() {
-      public boolean accept(final File pathName) {
+      public boolean accept(@NotNull final File pathName) {
         return pathName.getName().startsWith(baseName);
       }
     });
@@ -238,7 +241,8 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
     }
   }
 
-  private static File getDataFile(final File file) {
+  @NotNull
+  private static File getDataFile(@NotNull final File file) {
     return new File(file.getParentFile(), file.getName() + DATA_FILE_EXTENSION);
   }
 
@@ -284,13 +288,13 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
     void append(DataOutput out) throws IOException;
   }
   
-  public final void appendData(Key key, ValueDataAppender appender) throws IOException {
+  public final void appendData(Key key, @NotNull ValueDataAppender appender) throws IOException {
     synchronized (myEnumerator) {
       doAppendData(key, appender);
     }
   }
 
-  protected void doAppendData(Key key, ValueDataAppender appender) throws IOException {
+  protected void doAppendData(Key key, @NotNull ValueDataAppender appender) throws IOException {
     myEnumerator.markDirty(true);
 
     final AppendStream stream = myAppendCache.get(key);
@@ -308,6 +312,7 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
     }
   }
 
+  @NotNull
   public Collection<Key> getAllKeysWithExistingMapping() throws IOException {
     final List<Key> values = new ArrayList<Key>();
     processKeysWithExistingMapping(new CommonProcessors.CollectProcessor<Key>(values));
diff --git a/platform/util/src/com/intellij/util/io/PersistentStringEnumerator.java b/platform/util/src/com/intellij/util/io/PersistentStringEnumerator.java
index 247b48055517..89c46894993b 100644
--- a/platform/util/src/com/intellij/util/io/PersistentStringEnumerator.java
+++ b/platform/util/src/com/intellij/util/io/PersistentStringEnumerator.java
@@ -16,27 +16,29 @@
 package com.intellij.util.io;
 
 import com.intellij.util.containers.ConcurrentSLRUMap;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.io.IOException;
 
 public class PersistentStringEnumerator extends PersistentEnumeratorDelegate<String>{
-  private final ConcurrentSLRUMap<Integer, String> myIdToStringCache;
-  private final ConcurrentSLRUMap<Integer, Integer> myHashcodeToIdCache;
+  @Nullable private final ConcurrentSLRUMap<Integer, String> myIdToStringCache;
+  @Nullable private final ConcurrentSLRUMap<Integer, Integer> myHashcodeToIdCache;
 
-  public PersistentStringEnumerator(final File file) throws IOException {
+  public PersistentStringEnumerator(@NotNull final File file) throws IOException {
     this(file, 1024 * 4);
   }
 
-  public PersistentStringEnumerator(final File file, boolean cacheLastMappings) throws IOException {
+  public PersistentStringEnumerator(@NotNull final File file, boolean cacheLastMappings) throws IOException {
     this(file, 1024 * 4, cacheLastMappings);
   }
 
-  public PersistentStringEnumerator(final File file, final int initialSize) throws IOException {
+  public PersistentStringEnumerator(@NotNull final File file, final int initialSize) throws IOException {
     this(file, initialSize, false);
   }
 
-  private PersistentStringEnumerator(final File file, final int initialSize, boolean cacheLastMappings) throws IOException {
+  private PersistentStringEnumerator(@NotNull final File file, final int initialSize, boolean cacheLastMappings) throws IOException {
     super(file, new EnumeratorStringDescriptor(), initialSize);
     if (cacheLastMappings) {
       myIdToStringCache = new ConcurrentSLRUMap<Integer, String>(8192, 8192);
@@ -48,7 +50,7 @@ public class PersistentStringEnumerator extends PersistentEnumeratorDelegate<Str
   }
 
   @Override
-  public int enumerate(String value) throws IOException {
+  public int enumerate(@Nullable String value) throws IOException {
     int valueHashCode = -1;
 
     if (myHashcodeToIdCache != null && value != null) {
@@ -73,6 +75,7 @@ public class PersistentStringEnumerator extends PersistentEnumeratorDelegate<Str
     return enumerate;
   }
 
+  @Nullable
   @Override
   public String valueOf(int idx) throws IOException {
     if (myIdToStringCache != null) {
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotatedMemberIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotatedMemberIndex.java
index ec2e377773aa..5e770a4afea9 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotatedMemberIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotatedMemberIndex.java
@@ -18,6 +18,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * @author ilyas
@@ -25,6 +26,7 @@ import com.intellij.psi.stubs.StubIndexKey;
 public class GrAnnotatedMemberIndex extends StringStubIndexExtension<PsiElement> {
   public static final StubIndexKey<String, PsiElement> KEY = StubIndexKey.createIndexKey("gr.annot.members");
 
+  @NotNull
   public StubIndexKey<String, PsiElement> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotationMethodNameIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotationMethodNameIndex.java
index 0945a421540a..b5cdd93523d9 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotationMethodNameIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnnotationMethodNameIndex.java
@@ -17,6 +17,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrAnnotationMethod;
 
 /**
@@ -25,6 +26,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrAn
 public class GrAnnotationMethodNameIndex extends StringStubIndexExtension<GrAnnotationMethod> {
   public static final StubIndexKey<String, GrAnnotationMethod> KEY = StubIndexKey.createIndexKey("gr.annot.method.name");
 
+  @NotNull
   public StubIndexKey<String, GrAnnotationMethod> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnonymousClassIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnonymousClassIndex.java
index e39c3a00b1e4..4f414704b6e6 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnonymousClassIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrAnonymousClassIndex.java
@@ -18,6 +18,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.GrAnonymousClassDefinition;
 
 /**
@@ -26,6 +27,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.GrAnonymousC
 public class GrAnonymousClassIndex extends StringStubIndexExtension<GrAnonymousClassDefinition> {
   public static final StubIndexKey<String, GrAnonymousClassDefinition> KEY = StubIndexKey.createIndexKey("gr.anonymous.class");
 
+  @NotNull
   public StubIndexKey<String, GrAnonymousClassDefinition> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrDirectInheritorsIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrDirectInheritorsIndex.java
index cca4057a4f99..b5a4a443994e 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrDirectInheritorsIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrDirectInheritorsIndex.java
@@ -17,6 +17,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.GrReferenceList;
 
 /**
@@ -25,6 +26,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.GrReferenceL
 public class GrDirectInheritorsIndex extends StringStubIndexExtension<GrReferenceList> {
   public static final StubIndexKey<String, GrReferenceList> KEY = StubIndexKey.createIndexKey("gr.class.super");
 
+  @NotNull
   public StubIndexKey<String, GrReferenceList> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFieldNameIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFieldNameIndex.java
index 21dfc934672b..68a5f5742617 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFieldNameIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFieldNameIndex.java
@@ -17,6 +17,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.GrField;
 
 /**
@@ -25,6 +26,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.GrField;
 public class GrFieldNameIndex extends StringStubIndexExtension<GrField> {
   public static final StubIndexKey<String, GrField> KEY = StubIndexKey.createIndexKey("gr.field.name");
 
+  @NotNull
   public StubIndexKey<String, GrField> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullClassNameIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullClassNameIndex.java
index c4022cd66acb..a02c0210bae3 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullClassNameIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullClassNameIndex.java
@@ -20,6 +20,7 @@ import com.intellij.psi.PsiClass;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.psi.stubs.IntStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.impl.search.GrSourceFilterScope;
 
 import java.util.Collection;
@@ -35,6 +36,7 @@ public class GrFullClassNameIndex extends IntStubIndexExtension<PsiClass> {
     return ourInstance;
   }
 
+  @NotNull
   public StubIndexKey<Integer, PsiClass> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullScriptNameIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullScriptNameIndex.java
index a1f4771bc35c..0e6a13c93dbf 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullScriptNameIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrFullScriptNameIndex.java
@@ -19,6 +19,7 @@ import com.intellij.openapi.project.Project;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.psi.stubs.IntStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.GroovyFile;
 import org.jetbrains.plugins.groovy.lang.psi.impl.search.GrSourceFilterScope;
 
@@ -40,6 +41,7 @@ public class GrFullScriptNameIndex extends IntStubIndexExtension<GroovyFile> {
     return super.getVersion() + 1;
   }
 
+  @NotNull
   public StubIndexKey<Integer, GroovyFile> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrMethodNameIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrMethodNameIndex.java
index 08905ddb39dc..c98e9f167075 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrMethodNameIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrMethodNameIndex.java
@@ -17,6 +17,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrMethod;
 
 /**
@@ -25,6 +26,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrMe
 public class GrMethodNameIndex extends StringStubIndexExtension<GrMethod> {
   public static final StubIndexKey<String, GrMethod> KEY = StubIndexKey.createIndexKey("gr.method.name");
 
+  @NotNull
   public StubIndexKey<String, GrMethod> getKey() {
     return KEY;
   }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrScriptClassNameIndex.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrScriptClassNameIndex.java
index 9df7a1fdd5e2..25b5701af23a 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrScriptClassNameIndex.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/stubs/index/GrScriptClassNameIndex.java
@@ -17,6 +17,7 @@ package org.jetbrains.plugins.groovy.lang.psi.stubs.index;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.psi.GroovyFile;
 
 /**
@@ -25,6 +26,7 @@ import org.jetbrains.plugins.groovy.lang.psi.GroovyFile;
 public class GrScriptClassNameIndex extends StringStubIndexExtension<GroovyFile> {
   public static final StubIndexKey<String, GroovyFile> KEY = StubIndexKey.createIndexKey("gr.script.class");
 
+  @NotNull
   public StubIndexKey<String, GroovyFile> getKey() {
     return KEY;
   }
diff --git a/plugins/properties/src/com/intellij/lang/properties/psi/PropertyKeyIndex.java b/plugins/properties/src/com/intellij/lang/properties/psi/PropertyKeyIndex.java
index 6255ab8fc797..8667cf9dc25e 100644
--- a/plugins/properties/src/com/intellij/lang/properties/psi/PropertyKeyIndex.java
+++ b/plugins/properties/src/com/intellij/lang/properties/psi/PropertyKeyIndex.java
@@ -21,6 +21,7 @@ package com.intellij.lang.properties.psi;
 
 import com.intellij.psi.stubs.StringStubIndexExtension;
 import com.intellij.psi.stubs.StubIndexKey;
+import org.jetbrains.annotations.NotNull;
 
 public class PropertyKeyIndex extends StringStubIndexExtension<Property> {
   public static final StubIndexKey<String, Property> KEY = StubIndexKey.createIndexKey("properties.index");
@@ -31,6 +32,7 @@ public class PropertyKeyIndex extends StringStubIndexExtension<Property> {
     return ourInstance;
   }
 
+  @NotNull
   public StubIndexKey<String, Property> getKey() {
     return KEY;
   }