diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java
index 86788fec7af..288e92da85c 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java
@@ -47,10 +47,7 @@ import org.jetbrains.jet.lang.types.expressions.ExpressionTypingUtils;
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 
 import javax.inject.Inject;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 
 import static org.jetbrains.jet.lang.diagnostics.Errors.PROJECTION_ON_NON_CLASS_TYPE_ARGUMENT;
 import static org.jetbrains.jet.lang.diagnostics.Errors.SUPER_IS_NOT_AN_EXPRESSION;
@@ -520,9 +517,8 @@ public class CandidateResolver {
             @NotNull ResolutionContext<?> context
     ) {
         ExpressionReceiver receiverToCast = new ExpressionReceiver(JetPsiUtil.safeDeparenthesize(expression, false), actualType);
-        List<JetType> variants =
-                SmartCastUtils.getSmartCastVariantsExcludingReceiver(context.trace.getBindingContext(), context.dataFlowInfo,
-                                                                     receiverToCast);
+        Collection<JetType> variants = SmartCastUtils.getSmartCastVariantsExcludingReceiver(
+                context.trace.getBindingContext(), context.dataFlowInfo, receiverToCast);
         for (JetType possibleType : variants) {
             if (JetTypeChecker.DEFAULT.isSubtypeOf(possibleType, expectedType)) {
                 return possibleType;
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/smartcasts/SmartCastUtils.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/smartcasts/SmartCastUtils.java
index ded256bef5d..cd90343982d 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/smartcasts/SmartCastUtils.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/smartcasts/SmartCastUtils.java
@@ -32,6 +32,7 @@ import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.TypeUtils;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
@@ -68,7 +69,7 @@ public class SmartCastUtils {
      * @return variants @param receiverToCast may be cast to according to @param dataFlowInfo, @param receiverToCast itself is NOT included
      */
     @NotNull
-    public static List<JetType> getSmartCastVariantsExcludingReceiver(
+    public static Collection<JetType> getSmartCastVariantsExcludingReceiver(
             @NotNull BindingContext bindingContext,
             @NotNull DataFlowInfo dataFlowInfo,
             @NotNull ReceiverValue receiverToCast
@@ -77,23 +78,15 @@ public class SmartCastUtils {
             ThisReceiver receiver = (ThisReceiver) receiverToCast;
             assert receiver.exists();
             DataFlowValue dataFlowValue = DataFlowValueFactory.createDataFlowValue(receiver);
-            return collectSmartCastReceiverValues(dataFlowInfo, dataFlowValue);
+            return dataFlowInfo.getPossibleTypes(dataFlowValue);
         }
         else if (receiverToCast instanceof ExpressionReceiver) {
             DataFlowValue dataFlowValue = DataFlowValueFactory.createDataFlowValue(receiverToCast, bindingContext);
-            return collectSmartCastReceiverValues(dataFlowInfo, dataFlowValue);
+            return dataFlowInfo.getPossibleTypes(dataFlowValue);
         }
         return Collections.emptyList();
     }
 
-    @NotNull
-    private static List<JetType> collectSmartCastReceiverValues(
-            @NotNull DataFlowInfo dataFlowInfo,
-            @NotNull DataFlowValue dataFlowValue
-    ) {
-        return Lists.newArrayList(dataFlowInfo.getPossibleTypes(dataFlowValue));
-    }
-
     public static boolean isSubTypeBySmartCastIgnoringNullability(
             @NotNull ReceiverValue receiverArgument,
             @NotNull JetType receiverParameterType,
@@ -106,7 +99,7 @@ public class SmartCastUtils {
     @Nullable
     private static JetType getSmartCastSubType(
             @NotNull JetType receiverParameterType,
-            @NotNull List<JetType> smartCastTypes
+            @NotNull Collection<JetType> smartCastTypes
     ) {
         Set<JetType> subTypes = Sets.newHashSet();
         for (JetType smartCastType : smartCastTypes) {
@@ -136,7 +129,7 @@ public class SmartCastUtils {
             return false;
         }
 
-        List<JetType> smartCastTypesExcludingReceiver = getSmartCastVariantsExcludingReceiver(
+        Collection<JetType> smartCastTypesExcludingReceiver = getSmartCastVariantsExcludingReceiver(
                 context.trace.getBindingContext(), context.dataFlowInfo, receiver);
         JetType smartCastSubType = getSmartCastSubType(receiverParameterType, smartCastTypesExcludingReceiver);
         if (smartCastSubType == null) return false;