diff --git a/java/java-psi-api/src/com/intellij/psi/HierarchicalMethodSignature.java b/java/java-psi-api/src/com/intellij/psi/HierarchicalMethodSignature.java
index 22520b1fa6a9..3c920d38a5e6 100644
--- a/java/java-psi-api/src/com/intellij/psi/HierarchicalMethodSignature.java
+++ b/java/java-psi-api/src/com/intellij/psi/HierarchicalMethodSignature.java
@@ -27,8 +27,7 @@ import java.util.List;
  * @since 5.1
  */
 public abstract class HierarchicalMethodSignature extends MethodSignatureBackedByPsiMethod {
-
-  public HierarchicalMethodSignature(final MethodSignatureBackedByPsiMethod signature) {
+  public HierarchicalMethodSignature(@NotNull MethodSignatureBackedByPsiMethod signature) {
     super(signature.getMethod(), signature.getSubstitutor(), signature.isRaw(), 
           signature.getParameterTypes(), signature.getTypeParameters());
   }
diff --git a/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBackedByPsiMethod.java b/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBackedByPsiMethod.java
index 9f5985b54fcc..bfb3bea37651 100644
--- a/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBackedByPsiMethod.java
+++ b/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBackedByPsiMethod.java
@@ -26,10 +26,10 @@ public class MethodSignatureBackedByPsiMethod extends MethodSignatureBase {
   private final boolean myIsRaw;
 
   protected MethodSignatureBackedByPsiMethod(@NotNull PsiMethod method,
-                                             PsiSubstitutor substitutor,
+                                             @NotNull PsiSubstitutor substitutor,
                                              boolean isRaw,
-                                             PsiType[] parameterTypes,
-                                             PsiTypeParameter[] methodTypeParameters) {
+                                             @NotNull PsiType[] parameterTypes,
+                                             @NotNull PsiTypeParameter[] methodTypeParameters) {
     super(substitutor, parameterTypes, methodTypeParameters);
     myIsRaw = isRaw;
     if (!method.isValid()) {
@@ -67,11 +67,11 @@ public class MethodSignatureBackedByPsiMethod extends MethodSignatureBase {
     return myMethod;
   }
 
-  public static MethodSignatureBackedByPsiMethod create(PsiMethod method, PsiSubstitutor substitutor) {
+  public static MethodSignatureBackedByPsiMethod create(@NotNull PsiMethod method, @NotNull PsiSubstitutor substitutor) {
     return create(method, substitutor, PsiUtil.isRawSubstitutor(method, substitutor));
   }
 
-  public static MethodSignatureBackedByPsiMethod create(PsiMethod method, PsiSubstitutor substitutor, boolean isRaw) {
+  public static MethodSignatureBackedByPsiMethod create(@NotNull PsiMethod method, @NotNull PsiSubstitutor substitutor, boolean isRaw) {
     PsiTypeParameter[] methodTypeParameters = method.getTypeParameters();
     final PsiParameter[] parameters = method.getParameterList().getParameters();
     PsiType[] parameterTypes = new PsiType[parameters.length];
diff --git a/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBase.java b/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBase.java
index 25c8b6570c6b..f432bc747651 100644
--- a/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBase.java
+++ b/java/java-psi-api/src/com/intellij/psi/util/MethodSignatureBase.java
@@ -27,7 +27,7 @@ public abstract class MethodSignatureBase implements MethodSignature {
   private final PsiType[] myParameterTypes;
   protected final PsiTypeParameter[] myTypeParameters;
 
-  protected MethodSignatureBase(PsiSubstitutor substitutor, @NotNull PsiType[] parameterTypes, @NotNull PsiTypeParameter[] typeParameters) {
+  protected MethodSignatureBase(@NotNull PsiSubstitutor substitutor, @NotNull PsiType[] parameterTypes, @NotNull PsiTypeParameter[] typeParameters) {
     mySubstitutor = substitutor;
     myParameterTypes = parameterTypes.length == 0 ? PsiType.EMPTY_ARRAY : new PsiType[parameterTypes.length];
     for (int i = 0; i < parameterTypes.length; i++) {
diff --git a/platform/util/src/com/intellij/util/WalkingState.java b/platform/util/src/com/intellij/util/WalkingState.java
index 02af56ff126d..728b31501083 100644
--- a/platform/util/src/com/intellij/util/WalkingState.java
+++ b/platform/util/src/com/intellij/util/WalkingState.java
@@ -107,6 +107,9 @@ public class WalkingState<T> {
     stopped = true;
   }
 
+  /**
+   * process in the in-order fashion
+   */
   public static <T> boolean processAll(@NotNull T root, @NotNull TreeGuide<T> treeGuide, @NotNull final Processor<T> processor) {
     final boolean[] result = {true};
     new WalkingState<T>(treeGuide){