diff --git a/java/java-impl/src/com/intellij/psi/impl/source/resolve/reference/impl/providers/PackagePrefixFileSystemItemImpl.java b/java/java-impl/src/com/intellij/psi/impl/source/resolve/reference/impl/providers/PackagePrefixFileSystemItemImpl.java
index 8cd24dc08baf..f4f88c34679a 100644
--- a/java/java-impl/src/com/intellij/psi/impl/source/resolve/reference/impl/providers/PackagePrefixFileSystemItemImpl.java
+++ b/java/java-impl/src/com/intellij/psi/impl/source/resolve/reference/impl/providers/PackagePrefixFileSystemItemImpl.java
@@ -202,7 +202,7 @@ class PackagePrefixFileSystemItemImpl extends PsiElementBase implements PsiFileS
   }
 
   @Override
-  public boolean processChildren(final PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull final PsiElementProcessor<PsiFileSystemItem> processor) {
     if (myIndex == myPackages.length - 1) {
       return myDirectory.processChildren(processor);
     }
diff --git a/java/testFramework/src/com/intellij/mock/MockPsiDirectory.java b/java/testFramework/src/com/intellij/mock/MockPsiDirectory.java
index 0d84806498a4..57eb6e303dd7 100644
--- a/java/testFramework/src/com/intellij/mock/MockPsiDirectory.java
+++ b/java/testFramework/src/com/intellij/mock/MockPsiDirectory.java
@@ -135,7 +135,7 @@ public class MockPsiDirectory extends MockPsiElement implements PsiDirectory {
   }
 
   @Override
-  public boolean processChildren(final PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull final PsiElementProcessor<PsiFileSystemItem> processor) {
     throw new UnsupportedOperationException("Method processChildren is not yet implemented in " + getClass().getName());
   }
 
diff --git a/platform/core-api/src/com/intellij/psi/PsiFileSystemItem.java b/platform/core-api/src/com/intellij/psi/PsiFileSystemItem.java
index ce4c7b697641..78e0771657f8 100644
--- a/platform/core-api/src/com/intellij/psi/PsiFileSystemItem.java
+++ b/platform/core-api/src/com/intellij/psi/PsiFileSystemItem.java
@@ -36,8 +36,9 @@ public interface PsiFileSystemItem extends PsiCheckedRenameElement, NavigatableP
   VirtualFile getVirtualFile();
 
   @Override
-  @NotNull @NonNls
+  @NotNull
+  @NonNls
   String getName();
 
-  boolean processChildren(PsiElementProcessor<PsiFileSystemItem> processor);
+  boolean processChildren(@NotNull PsiElementProcessor<PsiFileSystemItem> processor);
 }
diff --git a/platform/core-api/src/com/intellij/psi/util/PsiUtilCore.java b/platform/core-api/src/com/intellij/psi/util/PsiUtilCore.java
index c2a2f6bbb8b1..7afe35ac94ca 100644
--- a/platform/core-api/src/com/intellij/psi/util/PsiUtilCore.java
+++ b/platform/core-api/src/com/intellij/psi/util/PsiUtilCore.java
@@ -671,7 +671,7 @@ public class PsiUtilCore {
     }
 
     @Override
-    public boolean processChildren(PsiElementProcessor<PsiFileSystemItem> processor) {
+    public boolean processChildren(@NotNull PsiElementProcessor<PsiFileSystemItem> processor) {
       throw createException();
     }
 
diff --git a/platform/core-impl/src/com/intellij/psi/impl/file/PsiBinaryFileImpl.java b/platform/core-impl/src/com/intellij/psi/impl/file/PsiBinaryFileImpl.java
index 6ec4a959f423..d19583e2ebbc 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/file/PsiBinaryFileImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/file/PsiBinaryFileImpl.java
@@ -55,7 +55,7 @@ public class PsiBinaryFileImpl extends PsiElementBase implements PsiBinaryFile,
   }
 
   @Override
-  public boolean processChildren(final PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull final PsiElementProcessor<PsiFileSystemItem> processor) {
     return true;
   }
 
diff --git a/platform/core-impl/src/com/intellij/psi/impl/file/PsiDirectoryImpl.java b/platform/core-impl/src/com/intellij/psi/impl/file/PsiDirectoryImpl.java
index 2d0a8e702abd..4f916fee54fb 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/file/PsiDirectoryImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/file/PsiDirectoryImpl.java
@@ -172,7 +172,7 @@ public class PsiDirectoryImpl extends PsiElementBase implements PsiDirectory, Qu
   }
 
   @Override
-  public boolean processChildren(PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull PsiElementProcessor<PsiFileSystemItem> processor) {
     checkValid();
 
     for (VirtualFile vFile : myFile.getChildren()) {
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
index 2e36a3c9a4cb..f095402a1394 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
@@ -124,7 +124,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
   }
 
   @Override
-  public boolean processChildren(final PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull final PsiElementProcessor<PsiFileSystemItem> processor) {
     return true;
   }
 
diff --git a/platform/lang-impl/src/com/intellij/psi/impl/source/LightPsiFileImpl.java b/platform/lang-impl/src/com/intellij/psi/impl/source/LightPsiFileImpl.java
index 578b93a39b2a..201c19bd5eb5 100644
--- a/platform/lang-impl/src/com/intellij/psi/impl/source/LightPsiFileImpl.java
+++ b/platform/lang-impl/src/com/intellij/psi/impl/source/LightPsiFileImpl.java
@@ -42,7 +42,7 @@ public abstract class LightPsiFileImpl extends PsiElementBase implements PsiFile
   }
 
   @Override
-  public boolean processChildren(final PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull final PsiElementProcessor<PsiFileSystemItem> processor) {
     return true;
   }
 
diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/VfsImplUtil.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/VfsImplUtil.java
index 66efc2946589..a41f3a39835e 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/VfsImplUtil.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/VfsImplUtil.java
@@ -125,7 +125,7 @@ public class VfsImplUtil {
 
   @Nullable
   private static Pair<NewVirtualFile, Iterable<String>> prepare(@NotNull NewVirtualFileSystem vfs, @NotNull String path) {
-    String normalizedPath = normalize(vfs, path);
+    String normalizedPath = vfs.normalize(path);
     if (StringUtil.isEmptyOrSpaces(normalizedPath)) {
       return null;
     }
diff --git a/platform/testFramework/src/com/intellij/mock/MockPsiFile.java b/platform/testFramework/src/com/intellij/mock/MockPsiFile.java
index 95e2094b84b5..8891e5e97d6a 100644
--- a/platform/testFramework/src/com/intellij/mock/MockPsiFile.java
+++ b/platform/testFramework/src/com/intellij/mock/MockPsiFile.java
@@ -63,7 +63,7 @@ public class MockPsiFile extends MockPsiElement implements PsiFile {
   }
 
   @Override
-  public boolean processChildren(final PsiElementProcessor<PsiFileSystemItem> processor) {
+  public boolean processChildren(@NotNull final PsiElementProcessor<PsiFileSystemItem> processor) {
     return true;
   }
 
diff --git a/plugins/properties/properties-psi-api/src/com/intellij/lang/properties/psi/PropertiesFile.java b/plugins/properties/properties-psi-api/src/com/intellij/lang/properties/psi/PropertiesFile.java
index 8be7d42ee118..18b89de410a6 100644
--- a/plugins/properties/properties-psi-api/src/com/intellij/lang/properties/psi/PropertiesFile.java
+++ b/plugins/properties/properties-psi-api/src/com/intellij/lang/properties/psi/PropertiesFile.java
@@ -45,7 +45,8 @@ public interface PropertiesFile {
   /**
    * @return All properties found in this file.
    */
-  @NotNull List<IProperty> getProperties();
+  @NotNull
+  List<IProperty> getProperties();
 
   /**
    *
@@ -57,13 +58,16 @@ public interface PropertiesFile {
   IProperty findPropertyByKey(@NotNull @NonNls String key);
 
   /**
-   * @param key
    * @return All properties found in this file with the name specified.
    */
-  @NotNull List<IProperty> findPropertiesByKey(@NotNull @NonNls String key);
+  @NotNull
+  List<IProperty> findPropertiesByKey(@NotNull @NonNls String key);
 
-  @NotNull ResourceBundle getResourceBundle();
-  @NotNull Locale getLocale();
+  @NotNull
+  ResourceBundle getResourceBundle();
+
+  @NotNull
+  Locale getLocale();
 
   /**
    * Adds property to the end of the file.
@@ -71,12 +75,12 @@ public interface PropertiesFile {
    * @param property to add. Typically you create the property via {@link PropertiesElementFactory}.
    * @return newly added property.
    * It is this value you use to do actual PSI work, e.g. call {@link PsiElement#delete()} to remove this property from the file.
-   * @throws IncorrectOperationException
-   * @deprecated
+   * @deprecated use {@link #addProperty(String, String)} instead
    * @see #addProperty(String, String)
    */
   @Deprecated
-  @NotNull PsiElement addProperty(@NotNull IProperty property) throws IncorrectOperationException;
+  @NotNull
+  PsiElement addProperty(@NotNull IProperty property) throws IncorrectOperationException;
 
   /**
    * Adds property to the the file after the specified property.
@@ -88,9 +92,9 @@ public interface PropertiesFile {
    * @param anchor property after which to add the new property
    * @return newly added property.
    * It is this value you use to do actual PSI work, e.g. call {@link PsiElement#delete()} to remove this property from the file.
-   * @throws IncorrectOperationException
    */
-  @NotNull PsiElement addPropertyAfter(@NotNull IProperty property, @Nullable IProperty anchor) throws IncorrectOperationException;
+  @NotNull
+  PsiElement addPropertyAfter(@NotNull IProperty property, @Nullable IProperty anchor) throws IncorrectOperationException;
 
   /**
    * Adds property to the the file after the specified property.
@@ -100,18 +104,21 @@ public interface PropertiesFile {
    * @param value of a property to add.
    * @param anchor property after which to add the new property
    * @return newly added property.
-   * @throws IncorrectOperationException
    */
-  IProperty addPropertyAfter(String key, String value, IProperty anchor) throws IncorrectOperationException;
+  @NotNull
+  IProperty addPropertyAfter(@NotNull String key, @NotNull String value, IProperty anchor) throws IncorrectOperationException;
 
-  IProperty addProperty(String key, String value);
+  @NotNull
+  IProperty addProperty(@NotNull String key, @NotNull String value);
 
   /**
    * @return Property key to the property value map.
    * Do not modify this map. It's no use anyway.
    */
-  @NotNull Map<String,String> getNamesMap();
+  @NotNull
+  Map<String,String> getNamesMap();
 
+  @NotNull
   String getName();
 
   VirtualFile getVirtualFile();
@@ -121,6 +128,7 @@ public interface PropertiesFile {
    */
   PsiDirectory getParent();
 
+  @NotNull
   Project getProject();
 
   String getText();
diff --git a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesFileImpl.java b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesFileImpl.java
index e00b4a1618f1..9fcdf8b23bbe 100644
--- a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesFileImpl.java
+++ b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesFileImpl.java
@@ -67,7 +67,8 @@ public class PropertiesFileImpl extends PsiFileBase implements PropertiesFile {
     if (stub != null) {
       PropertiesListStub propertiesListStub = stub.findChildStubByType(PropertiesElementTypes.PROPERTIES_LIST);
       propertiesList = propertiesListStub == null ? null : propertiesListStub.getPsi();
-    } else {
+    }
+    else {
       propertiesList = PsiTreeUtil.findChildOfType(this, PropertiesList.class);
     }
     return Collections.unmodifiableList(PsiTreeUtil.getStubChildrenOfTypeAsList(propertiesList, Property.class));
@@ -123,10 +124,8 @@ public class PropertiesFileImpl extends PsiFileBase implements PropertiesFile {
     List<IProperty> properties = getProperties();
     ASTNode anchorBefore = anchor == null ? properties.isEmpty() ? null : properties.get(0).getPsiElement().getNode()
                            : anchor.getPsiElement().getNode().getTreeNext();
-    if (anchorBefore != null) {
-      if (anchorBefore.getElementType() == TokenType.WHITE_SPACE) {
-        anchorBefore = anchorBefore.getTreeNext();
-      }
+    if (anchorBefore != null && anchorBefore.getElementType() == TokenType.WHITE_SPACE) {
+      anchorBefore = anchorBefore.getTreeNext();
     }
     if (anchorBefore == null && haveToAddNewLine()) {
       insertLineBreakBefore(null);
@@ -140,21 +139,22 @@ public class PropertiesFileImpl extends PsiFileBase implements PropertiesFile {
 
   @NotNull
   @Override
-  public IProperty addProperty(String key, String value) {
+  public IProperty addProperty(@NotNull String key, @NotNull String value) {
     return (IProperty)addProperty(PropertiesElementFactory.createProperty(getProject(), key, value, null));
   }
 
   @NotNull
   @Override
-  public IProperty addPropertyAfter(String key, String value, @Nullable IProperty anchor) {
+  public IProperty addPropertyAfter(@NotNull String key, @NotNull String value, @Nullable IProperty anchor) {
     return (IProperty)addPropertyAfter(PropertiesElementFactory.createProperty(getProject(), key, value, null), anchor);
   }
 
-  private void insertLineBreakBefore(final ASTNode anchorBefore) {
+  private void insertLineBreakBefore(ASTNode anchorBefore) {
     ASTNode propertiesList = getPropertiesList();
     if (anchorBefore == null && propertiesList.getFirstChildNode() == null) {
       getNode().addChild(ASTFactory.whitespace("\n"), propertiesList);
-    } else {
+    }
+    else {
       propertiesList.addChild(ASTFactory.whitespace("\n"), anchorBefore);
     }
   }
@@ -199,14 +199,13 @@ public class PropertiesFileImpl extends PsiFileBase implements PropertiesFile {
     return ContainerUtil.getLastItem(properties);
   }
 
+  @NotNull
   private Stream<? extends IProperty> propertiesByKey(@NotNull String key) {
     if (shouldReadIndex()) {
       return PropertyKeyIndex.getInstance().get(key, getProject(), GlobalSearchScope.fileScope(this)).stream();
     }
-    else {
-      // see PropertiesElementFactory.createPropertiesFile(Project, Properties, String)
-      return getProperties().stream().filter(p -> key.equals(p.getUnescapedKey()));
-    }
+    // see PropertiesElementFactory.createPropertiesFile(Project, Properties, String)
+    return getProperties().stream().filter(p -> key.equals(p.getUnescapedKey()));
   }
 
   private boolean shouldReadIndex() {
diff --git a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/xml/XmlPropertiesFileImpl.java b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/xml/XmlPropertiesFileImpl.java
index 866ecabc96e2..50884615cbc5 100644
--- a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/xml/XmlPropertiesFileImpl.java
+++ b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/xml/XmlPropertiesFileImpl.java
@@ -140,8 +140,9 @@ public class XmlPropertiesFileImpl extends XmlPropertiesFile {
     return addPropertyAfter(property.getKey(), property.getValue(), anchor).getPsiElement().getNavigationElement();
   }
 
+  @NotNull
   @Override
-  public IProperty addPropertyAfter(String key, String value, IProperty anchor) {
+  public IProperty addPropertyAfter(@NotNull String key, @NotNull String value, IProperty anchor) {
     return addPropertyAfter(key, value, anchor, true);
   }
 
@@ -156,7 +157,7 @@ public class XmlPropertiesFileImpl extends XmlPropertiesFile {
 
   @NotNull
   @Override
-  public IProperty addProperty(String key, String value) {
+  public IProperty addProperty(@NotNull String key, @NotNull String value) {
     final XmlTag entry = createPropertyTag(key, value);
     synchronized (myLock) {
       ensurePropertiesLoaded();
@@ -221,6 +222,7 @@ public class XmlPropertiesFileImpl extends XmlPropertiesFile {
     return result;
   }
 
+  @NotNull
   @Override
   public String getName() {
     return getContainingFile().getName();
@@ -236,6 +238,7 @@ public class XmlPropertiesFileImpl extends XmlPropertiesFile {
     return getContainingFile().getParent();
   }
 
+  @NotNull
   @Override
   public Project getProject() {
     return getContainingFile().getProject();
diff --git a/plugins/properties/src/com/intellij/lang/properties/editor/PropertiesCopyHandler.java b/plugins/properties/src/com/intellij/lang/properties/editor/PropertiesCopyHandler.java
index 4ccf8a558069..092e8d24d24a 100644
--- a/plugins/properties/src/com/intellij/lang/properties/editor/PropertiesCopyHandler.java
+++ b/plugins/properties/src/com/intellij/lang/properties/editor/PropertiesCopyHandler.java
@@ -314,7 +314,7 @@ public class PropertiesCopyHandler extends CopyHandlerDelegateBase {
     }
 
     @Override
-    public boolean processChildren(PsiElementProcessor<PsiFileSystemItem> processor) {
+    public boolean processChildren(@NotNull PsiElementProcessor<PsiFileSystemItem> processor) {
       for (PropertiesFile propertiesFile : myResourceBundle.getPropertiesFiles()) {
         if (!propertiesFile.getContainingFile().processChildren(processor)) {
           return false;