diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/CastingLookupElementDecorator.java b/java/java-impl/src/com/intellij/codeInsight/completion/CastingLookupElementDecorator.java
index c9e5c70a7bfd..9b97a9451a2b 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/CastingLookupElementDecorator.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/CastingLookupElementDecorator.java
@@ -17,6 +17,7 @@ package com.intellij.codeInsight.completion;
 
 import com.intellij.codeInsight.lookup.*;
 import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.util.ClassConditionKey;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiType;
 import com.intellij.psi.codeStyle.CodeStyleSettings;
@@ -27,6 +28,8 @@ import org.jetbrains.annotations.Nullable;
  * @author peter
  */
 public class CastingLookupElementDecorator extends LookupElementDecorator<LookupElement> implements TypedLookupItem {
+  public static final ClassConditionKey<CastingLookupElementDecorator> CLASS_CONDITION_KEY = ClassConditionKey.create(CastingLookupElementDecorator.class);
+
   private final LookupElement myCastItem;
   private final PsiType myCastType;
 
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaChainLookupElement.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaChainLookupElement.java
index e2afa96bbdfe..62c4e060a265 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaChainLookupElement.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaChainLookupElement.java
@@ -18,6 +18,7 @@ package com.intellij.codeInsight.completion;
 import com.intellij.codeInsight.lookup.*;
 import com.intellij.featureStatistics.FeatureUsageTracker;
 import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.util.ClassConditionKey;
 import com.intellij.psi.*;
 import com.intellij.psi.codeStyle.CodeStyleSettingsManager;
 import com.intellij.psi.util.PsiTreeUtil;
@@ -30,6 +31,7 @@ import java.util.Set;
  * @author peter
  */
 public class JavaChainLookupElement extends LookupElementDecorator<LookupElement> implements TypedLookupItem {
+  public static final ClassConditionKey<JavaChainLookupElement> CLASS_CONDITION_KEY = ClassConditionKey.create(JavaChainLookupElement.class);
   private final LookupElement myQualifier;
 
   private JavaChainLookupElement(LookupElement qualifier, LookupElement main) {
@@ -72,7 +74,7 @@ public class JavaChainLookupElement extends LookupElementDecorator<LookupElement
     final LookupElementPresentation qualifierPresentation = new LookupElementPresentation();
     myQualifier.renderElement(qualifierPresentation);
     String name = maybeAddParentheses(qualifierPresentation.getItemText());
-    final String qualifierText = myQualifier.as(CastingLookupElementDecorator.class) != null ? "(" + name + ")" : name;
+    final String qualifierText = myQualifier.as(CastingLookupElementDecorator.CLASS_CONDITION_KEY) != null ? "(" + name + ")" : name;
     presentation.setItemText(qualifierText + "." + presentation.getItemText());
   }
 
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java
index 50449b41a2f3..a46a650d7e53 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java
@@ -242,7 +242,7 @@ public class JavaCompletionContributor extends CompletionContributor {
                 result.addElement(TailTypeDecorator.withTail(element, TailType.createSimpleTailType(':')));
               }
               else {
-                final LookupItem item = element.as(LookupItem.class);
+                final LookupItem item = element.as(LookupItem.CLASS_CONDITION_KEY);
                 if (originalFile instanceof PsiJavaCodeReferenceCodeFragment &&
                     !((PsiJavaCodeReferenceCodeFragment)originalFile).isClassesAccepted() && item != null) {
                   item.setTailType(TailType.NONE);
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionUtil.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionUtil.java
index e06d2bec4832..97903ef907b9 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionUtil.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionUtil.java
@@ -974,7 +974,7 @@ public class JavaCompletionUtil {
 
     if (smart || needRightParenth && addCompletionChar) {
       TailType toInsert = tailType;
-      LookupItem lookupItem = item.as(LookupItem.class);
+      LookupItem lookupItem = item.as(LookupItem.CLASS_CONDITION_KEY);
       if (lookupItem == null || lookupItem.getAttribute(LookupItem.TAIL_TYPE_ATTR) != TailType.UNKNOWN) {
         if (!hasTail && item.getObject() instanceof PsiMethod && ((PsiMethod)item.getObject()).getReturnType() == PsiType.VOID) {
           PsiDocumentManager.getInstance(file.getProject()).commitAllDocuments();
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java
index 1cb7537a2901..d91b3aba7e2b 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java
@@ -22,6 +22,7 @@ import com.intellij.codeInsight.lookup.*;
 import com.intellij.codeInsight.lookup.impl.JavaElementLookupRenderer;
 import com.intellij.featureStatistics.FeatureUsageTracker;
 import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.util.ClassConditionKey;
 import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
@@ -34,6 +35,7 @@ import org.jetbrains.annotations.Nullable;
  * @author peter
  */
 public class JavaMethodCallElement extends LookupItem<PsiMethod> implements TypedLookupItem, StaticallyImportable {
+  public static final ClassConditionKey<JavaMethodCallElement> CLASS_CONDITION_KEY = ClassConditionKey.create(JavaMethodCallElement.class);
   private static final Key<PsiSubstitutor> INFERENCE_SUBSTITUTOR = Key.create("INFERENCE_SUBSTITUTOR");
   @Nullable private final PsiClass myContainingClass;
   private final PsiMethod myMethod;
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodMergingContributor.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodMergingContributor.java
index 513302500f98..74bdc7ccc0a5 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodMergingContributor.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodMergingContributor.java
@@ -49,7 +49,7 @@ public class JavaMethodMergingContributor extends CompletionContributor {
         }
 
         final PsiMethod method = (PsiMethod)o;
-        final JavaChainLookupElement chain = item.as(JavaChainLookupElement.class);
+        final JavaChainLookupElement chain = item.as(JavaChainLookupElement.CLASS_CONDITION_KEY);
         final String name = method.getName() + "#" + (chain == null ? "" : chain.getQualifier().getLookupString());
         if (commonName != null && !commonName.equals(name)) {
           return AutoCompletionDecision.SHOW_LOOKUP;
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/PreferNonGenericWeigher.java b/java/java-impl/src/com/intellij/codeInsight/completion/PreferNonGenericWeigher.java
index 4a9c69361352..a3f8154cca60 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/PreferNonGenericWeigher.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/PreferNonGenericWeigher.java
@@ -21,7 +21,6 @@ import com.intellij.psi.PsiMethod;
 import com.intellij.psi.PsiType;
 import com.intellij.psi.PsiTypeParameter;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 /**
  * @author peter
@@ -29,13 +28,10 @@ import org.jetbrains.annotations.Nullable;
 public class PreferNonGenericWeigher extends CompletionWeigher {
 
   public Comparable weigh(@NotNull final LookupElement item, @NotNull final CompletionLocation location) {
-    if (location == null) {
-      return null;
-    }
     final Object object = item.getObject();
     if (object instanceof PsiMethod) {
       PsiType type = ((PsiMethod)object).getReturnType();
-      final JavaMethodCallElement callItem = item.as(JavaMethodCallElement.class);
+      final JavaMethodCallElement callItem = item.as(JavaMethodCallElement.CLASS_CONDITION_KEY);
       if (callItem != null) {
         type = callItem.getSubstitutor().substitute(type);
       }
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/ReferenceExpressionCompletionContributor.java b/java/java-impl/src/com/intellij/codeInsight/completion/ReferenceExpressionCompletionContributor.java
index a420ee3fd001..1f92244fec69 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/ReferenceExpressionCompletionContributor.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/ReferenceExpressionCompletionContributor.java
@@ -167,7 +167,7 @@ public class ReferenceExpressionCompletionContributor {
       }), false, parameters);
     for (LookupElement lookupElement : elements) {
       if (lookupElement.getObject() instanceof PsiMethod) {
-        final JavaMethodCallElement item = lookupElement.as(JavaMethodCallElement.class);
+        final JavaMethodCallElement item = lookupElement.as(JavaMethodCallElement.CLASS_CONDITION_KEY);
         assert item != null;
         final PsiMethod method = (PsiMethod)lookupElement.getObject();
         if (SmartCompletionDecorator.hasUnboundTypeParams(method)) {
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/SmartCompletionDecorator.java b/java/java-impl/src/com/intellij/codeInsight/completion/SmartCompletionDecorator.java
index 281827fac929..ef32d2520c77 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/SmartCompletionDecorator.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/SmartCompletionDecorator.java
@@ -59,7 +59,7 @@ public class SmartCompletionDecorator extends TailTypeDecorator<LookupElement> {
     }
 
     LookupElement delegate = getDelegate();
-    LookupItem item = as(LookupItem.class);
+    LookupItem item = as(LookupItem.CLASS_CONDITION_KEY);
     Object object = delegate.getObject();
     if (!CodeInsightSettings.getInstance().AUTOINSERT_PAIR_BRACKET && (object instanceof PsiMethod || object instanceof PsiClass)) {
       return TailType.NONE;
diff --git a/platform/lang-api/src/com/intellij/codeInsight/completion/PrioritizedLookupElement.java b/platform/lang-api/src/com/intellij/codeInsight/completion/PrioritizedLookupElement.java
index 13df562fcc7b..07718c7181fd 100644
--- a/platform/lang-api/src/com/intellij/codeInsight/completion/PrioritizedLookupElement.java
+++ b/platform/lang-api/src/com/intellij/codeInsight/completion/PrioritizedLookupElement.java
@@ -18,6 +18,7 @@ package com.intellij.codeInsight.completion;
 
 import com.intellij.codeInsight.lookup.LookupElement;
 import com.intellij.codeInsight.lookup.LookupElementDecorator;
+import com.intellij.openapi.util.ClassConditionKey;
 import org.jetbrains.annotations.Nullable;
 
 /**
@@ -28,6 +29,7 @@ import org.jetbrains.annotations.Nullable;
  * @author peter
  */
 public class PrioritizedLookupElement<T extends LookupElement> extends LookupElementDecorator<T> {
+  public static final ClassConditionKey<PrioritizedLookupElement> CLASS_CONDITION_KEY = ClassConditionKey.create(PrioritizedLookupElement.class);
   private final double myPriority;
   private final int myGrouping;
 
diff --git a/platform/lang-api/src/com/intellij/codeInsight/lookup/AutoCompletionPolicy.java b/platform/lang-api/src/com/intellij/codeInsight/lookup/AutoCompletionPolicy.java
index 96c7ac02fc49..e9b76972dcde 100644
--- a/platform/lang-api/src/com/intellij/codeInsight/lookup/AutoCompletionPolicy.java
+++ b/platform/lang-api/src/com/intellij/codeInsight/lookup/AutoCompletionPolicy.java
@@ -15,6 +15,7 @@
  */
 package com.intellij.codeInsight.lookup;
 
+import com.intellij.openapi.util.ClassConditionKey;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -56,7 +57,7 @@ public enum AutoCompletionPolicy {
 
   @Nullable
   public static AutoCompletionPolicy getPolicy(LookupElement element) {
-    final PolicyDecorator decorator = element.as(PolicyDecorator.class);
+    final PolicyDecorator decorator = element.as(PolicyDecorator.CLASS_CONDITION_KEY);
     if (decorator != null) {
       return decorator.myPolicy;
     }
@@ -64,6 +65,7 @@ public enum AutoCompletionPolicy {
   }
 
   private static class PolicyDecorator extends LookupElementDecorator<LookupElement> {
+    public static final ClassConditionKey<PolicyDecorator> CLASS_CONDITION_KEY = ClassConditionKey.create(PolicyDecorator.class);
     private final AutoCompletionPolicy myPolicy;
 
     public PolicyDecorator(LookupElement element, AutoCompletionPolicy policy) {
diff --git a/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElement.java b/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElement.java
index 10ad5a4984c0..af5581c3e8ff 100644
--- a/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElement.java
+++ b/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElement.java
@@ -17,6 +17,7 @@ package com.intellij.codeInsight.lookup;
 
 import com.intellij.codeInsight.completion.InsertionContext;
 import com.intellij.codeInsight.completion.PrefixMatcher;
+import com.intellij.openapi.util.ClassConditionKey;
 import com.intellij.openapi.util.UserDataHolderBase;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
@@ -82,10 +83,18 @@ public abstract class LookupElement extends UserDataHolderBase {
     presentation.setItemText(getLookupString());
   }
 
+  /**
+   * use {@link #as(com.intellij.openapi.util.ClassConditionKey)} instead
+   */
+  @Deprecated
   @Nullable
-  public <T> T as(Class<T> aClass) {
-    //noinspection unchecked
-    return aClass.isInstance(this) ? (T) this : null;
+  public final <T> T as(Class<T> aClass) {
+    return as(ClassConditionKey.create(aClass));
+  }
+
+  @Nullable
+  public <T> T as(ClassConditionKey<T> conditionKey) {
+    return conditionKey.isInstance(this) ? (T) this : null;
   }
   
   public boolean isCaseSensitive() {
diff --git a/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElementDecorator.java b/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElementDecorator.java
index 1aab873ff062..3584b38fb685 100644
--- a/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElementDecorator.java
+++ b/platform/lang-api/src/com/intellij/codeInsight/lookup/LookupElementDecorator.java
@@ -19,6 +19,7 @@ import com.intellij.codeInsight.completion.CompletionService;
 import com.intellij.codeInsight.completion.InsertHandler;
 import com.intellij.codeInsight.completion.InsertionContext;
 import com.intellij.codeInsight.completion.PrefixMatcher;
+import com.intellij.openapi.util.ClassConditionKey;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Set;
@@ -108,9 +109,9 @@ public abstract class LookupElementDecorator<T extends LookupElement> extends Lo
   }
 
   @Override
-  public <T> T as(Class<T> aClass) {
-    final T t = super.as(aClass);
-    return t == null ? myDelegate.as(aClass) : t;
+  public <T> T as(ClassConditionKey<T> conditionKey) {
+    final T t = super.as(conditionKey);
+    return t == null ? myDelegate.as(conditionKey) : t;
   }
   
   public boolean isCaseSensitive() {
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/CodeCompletionHandlerBase.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/CodeCompletionHandlerBase.java
index 9035ea961bb7..af8c10fd19a6 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/CodeCompletionHandlerBase.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/CodeCompletionHandlerBase.java
@@ -452,7 +452,7 @@ public class CodeCompletionHandlerBase implements CodeInsightActionHandler {
       return policy;
     }
 
-    final LookupItem item = element.as(LookupItem.class);
+    final LookupItem item = element.as(LookupItem.CLASS_CONDITION_KEY);
     if (item != null) {
       return item.getAutoCompletionPolicy();
     }
@@ -505,8 +505,8 @@ public class CodeCompletionHandlerBase implements CodeInsightActionHandler {
       protected void run(Result result) throws Throwable {
         String uniqueText = _uniqueText;
 
-        if (item.getObject() instanceof DeferredUserLookupValue && item.as(LookupItem.class) != null) {
-          if (!((DeferredUserLookupValue)item.getObject()).handleUserSelection(item.as(LookupItem.class), context.getProject())) {
+        if (item.getObject() instanceof DeferredUserLookupValue && item.as(LookupItem.CLASS_CONDITION_KEY) != null) {
+          if (!((DeferredUserLookupValue)item.getObject()).handleUserSelection(item.as(LookupItem.CLASS_CONDITION_KEY), context.getProject())) {
             return;
           }
 
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/GroupingWeigher.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/GroupingWeigher.java
index 10d7fda3fd4b..a452c63ec561 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/GroupingWeigher.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/GroupingWeigher.java
@@ -18,7 +18,6 @@ package com.intellij.codeInsight.completion;
 
 import com.intellij.codeInsight.lookup.LookupElement;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 /**
  * @author peter
@@ -26,10 +25,7 @@ import org.jetbrains.annotations.Nullable;
 public class GroupingWeigher extends CompletionWeigher {
   @Override
   public Integer weigh(@NotNull LookupElement element, @NotNull CompletionLocation location) {
-    if (location == null) {
-      return null;
-    }
-    final PrioritizedLookupElement prioritized = element.as(PrioritizedLookupElement.class);
+    final PrioritizedLookupElement prioritized = element.as(PrioritizedLookupElement.CLASS_CONDITION_KEY);
     if (prioritized != null) {
       return -prioritized.getGrouping();
     }
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/LookupItem.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/LookupItem.java
index 13dd3f790f53..113fc37dd4f2 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/LookupItem.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/LookupItem.java
@@ -25,6 +25,7 @@ import com.intellij.codeInsight.completion.InsertionContext;
 import com.intellij.codeInsight.lookup.impl.ElementLookupRenderer;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.extensions.Extensions;
+import com.intellij.openapi.util.ClassConditionKey;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Key;
 import com.intellij.util.containers.ContainerUtil;
@@ -42,6 +43,8 @@ import java.util.Set;
  * This class represents an item of a lookup list.
  */
 public class LookupItem<T> extends MutableLookupElement<T> implements Comparable {
+  public static final ClassConditionKey<LookupItem> CLASS_CONDITION_KEY = ClassConditionKey.create(LookupItem.class);
+
   public static final Object HIGHLIGHTED_ATTR = Key.create("highlighted");
   public static final Object ICON_ATTR = Key.create("icon");
   public static final Object TYPE_TEXT_ATTR = Key.create("typeText");
@@ -358,14 +361,6 @@ public class LookupItem<T> extends MutableLookupElement<T> implements Comparable
     return myAllLookupStrings;
   }
 
-  public void copyAttributes(final LookupItem item) {
-    if (myAttributes == null) {
-      if (item.myAttributes == null) return;
-      myAttributes = new HashMap<Object, Object>(5);
-    }
-    myAttributes.putAll(item.myAttributes);
-  }
-
   @Override
   public boolean isCaseSensitive() {
     return !Boolean.TRUE.equals(getAttribute(CASE_INSENSITIVE));
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/TailTypeDecorator.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/TailTypeDecorator.java
index 264afef7d421..f5c649b16ee1 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/TailTypeDecorator.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/TailTypeDecorator.java
@@ -46,7 +46,7 @@ public abstract class TailTypeDecorator<T extends LookupElement> extends LookupE
     final LookupElement delegate = getDelegate();
     final TailType tailType = computeTailType(context);
 
-    final LookupItem lookupItem = delegate.as(LookupItem.class);
+    final LookupItem lookupItem = delegate.as(LookupItem.CLASS_CONDITION_KEY);
     if (lookupItem != null && tailType != null) {
       lookupItem.setTailType(TailType.UNKNOWN);
     }
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
index bec42fbd1224..7b334b63176a 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
@@ -593,8 +593,8 @@ public class LookupImpl extends LightweightHint implements Lookup, Disposable {
     if (item == null ||
         item instanceof EmptyLookupItem ||
         item.getObject() instanceof DeferredUserLookupValue &&
-        item.as(LookupItem.class) != null &&
-        !((DeferredUserLookupValue)item.getObject()).handleUserSelection(item.as(LookupItem.class), myProject)) {
+        item.as(LookupItem.CLASS_CONDITION_KEY) != null &&
+        !((DeferredUserLookupValue)item.getObject()).handleUserSelection(item.as(LookupItem.CLASS_CONDITION_KEY), myProject)) {
       fireItemSelected(null, completionChar);
       return;
     }
diff --git a/platform/platform-api/src/com/intellij/openapi/util/ClassConditionKey.java b/platform/platform-api/src/com/intellij/openapi/util/ClassConditionKey.java
new file mode 100644
index 000000000000..fb47b5f635e3
--- /dev/null
+++ b/platform/platform-api/src/com/intellij/openapi/util/ClassConditionKey.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2000-2011 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.openapi.util;
+
+import com.intellij.util.InstanceofCheckerGenerator;
+
+/**
+ * @author peter
+ */
+public class ClassConditionKey<T> {
+  private final Condition<Object> myCondition;
+  private final Class<T> myConditionClass;
+
+  private ClassConditionKey(Class<T> aClass) {
+    myCondition = InstanceofCheckerGenerator.getInstance().getInstanceofChecker(aClass);
+    myConditionClass = aClass;
+  }
+
+  public static <T> ClassConditionKey<T> create(Class<T> aClass) {
+    return new ClassConditionKey<T>(aClass);
+  }
+
+  public boolean isInstance(Object o) {
+    return myCondition.value(o);
+  }
+
+  @Override
+  public String toString() {
+    return myConditionClass.getName();
+  }
+}
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GrMethodMergingContributor.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GrMethodMergingContributor.java
index 9af0d1b949b3..08bc54b2eccc 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GrMethodMergingContributor.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GrMethodMergingContributor.java
@@ -57,7 +57,7 @@ public class GrMethodMergingContributor extends CompletionContributor {
         }
 
         final PsiMethod method = (PsiMethod)o;
-        final JavaChainLookupElement chain = item.as(JavaChainLookupElement.class);
+        final JavaChainLookupElement chain = item.as(JavaChainLookupElement.CLASS_CONDITION_KEY);
         final String name = method.getName() + "#" + (chain == null ? "" : chain.getQualifier().getLookupString());
 
         if (commonName != null && !commonName.equals(name)) {