diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
index f784e02d460..e6c80836b46 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
@@ -151,6 +151,8 @@ public class JetTypeMapper {
             register(JetStandardLibraryNames.ENUM, JL_ENUM_TYPE, JL_ENUM_TYPE);
             register(JetStandardLibraryNames.ITERABLE, JL_ITERABLE_TYPE, JL_ITERABLE_TYPE);
             register(JetStandardLibraryNames.ITERATOR, JL_ITERATOR_TYPE, JL_ITERATOR_TYPE);
+            register(JetStandardLibraryNames.MUTABLE_ITERABLE, JL_ITERABLE_TYPE, JL_ITERABLE_TYPE);
+            register(JetStandardLibraryNames.MUTABLE_ITERATOR, JL_ITERATOR_TYPE, JL_ITERATOR_TYPE);
 
             for (JvmPrimitiveType jvmPrimitiveType : JvmPrimitiveType.values()) {
                 PrimitiveType primitiveType = jvmPrimitiveType.getPrimitiveType();
diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
index b7e07542a26..9a6326a5cc9 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
@@ -1686,7 +1686,8 @@ public class JavaDescriptorResolver implements DependencyClassByQualifiedNameRes
             transformedType = semanticServices.getTypeTransformer().transformToType(returnTypeFromAnnotation, typeVariableResolver);
         }
         else {
-            transformedType = semanticServices.getTypeTransformer().transformToType(returnType, typeVariableResolver);
+            transformedType = semanticServices.getTypeTransformer().transformToType(
+                    returnType, JavaTypeTransformer.TypeUsage.MEMBER_SIGNATURE_COVARIANT, typeVariableResolver);
         }
         if (method.getJetMethod().returnTypeNullable()) {
             return TypeUtils.makeNullableAsSpecified(transformedType, true);
diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaTypeTransformer.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaTypeTransformer.java
index 98bba84a679..ca684690294 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaTypeTransformer.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaTypeTransformer.java
@@ -17,6 +17,7 @@
 package org.jetbrains.jet.lang.resolve.java;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.intellij.psi.*;
 import org.jetbrains.annotations.NotNull;
@@ -59,6 +60,7 @@ public class JavaTypeTransformer {
 
     private Map<String, JetType> primitiveTypesMap;
     private Map<FqName, ClassDescriptor> classDescriptorMap;
+    private Map<FqName, ClassDescriptor> classDescriptorMapForCovariantPositions;
 
 
     @NotNull
@@ -157,7 +159,7 @@ public class JavaTypeTransformer {
                     // 'L extends List<T>' in Java is a List<T> in Kotlin, not a List<T?>
                     boolean nullable = !EnumSet.of(SUPERTYPE_ARGUMENT, SUPERTYPE).contains(howThisTypeIsUsed);
 
-                    ClassDescriptor classData = getKotlinAnalog(new FqName(psiClass.getQualifiedName()));
+                    ClassDescriptor classData = getKotlinAnalog(new FqName(psiClass.getQualifiedName()), howThisTypeIsUsed);
 
                     if (classData == null) {
                         classData = resolver.resolveClass(new FqName(psiClass.getQualifiedName()), DescriptorSearchRule.INCLUDE_KOTLIN);
@@ -255,7 +257,7 @@ public class JavaTypeTransformer {
 
     public Map<FqName, ClassDescriptor> getClassDescriptorMap() {
         if (classDescriptorMap == null) {
-            classDescriptorMap = new HashMap<FqName, ClassDescriptor>();
+            classDescriptorMap = Maps.newHashMap();
             for (JvmPrimitiveType jvmPrimitiveType : JvmPrimitiveType.values()) {
                 PrimitiveType primitiveType = jvmPrimitiveType.getPrimitiveType();
                 classDescriptorMap.put(jvmPrimitiveType.getWrapper().getFqName(), JetStandardLibrary.getInstance().getPrimitiveClassDescriptor(primitiveType));
@@ -273,8 +275,23 @@ public class JavaTypeTransformer {
         return classDescriptorMap;
     }
 
+    public Map<FqName, ClassDescriptor> getClassDescriptorMapForCovariantPositions() {
+        if (classDescriptorMapForCovariantPositions == null) {
+            classDescriptorMapForCovariantPositions = Maps.newHashMap();
+            classDescriptorMapForCovariantPositions.put(new FqName("java.lang.Iterable"), JetStandardLibrary.getInstance().getMutableIterable());
+            classDescriptorMapForCovariantPositions.put(new FqName("java.util.Iterator"), JetStandardLibrary.getInstance().getMutableIterator());
+        }
+        return classDescriptorMapForCovariantPositions;
+    }
+
     @Nullable
-    public ClassDescriptor getKotlinAnalog(@NotNull FqName fqName) {
+    public ClassDescriptor getKotlinAnalog(@NotNull FqName fqName, @NotNull TypeUsage typeUsage) {
+        if (typeUsage == MEMBER_SIGNATURE_COVARIANT) {
+            ClassDescriptor descriptor = getClassDescriptorMapForCovariantPositions().get(fqName);
+            if (descriptor != null) {
+                return descriptor;
+            }
+        }
         return getClassDescriptorMap().get(fqName);
     }
 
diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JetTypeJetSignatureReader.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JetTypeJetSignatureReader.java
index 245a751d018..3d993f32329 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JetTypeJetSignatureReader.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JetTypeJetSignatureReader.java
@@ -95,7 +95,7 @@ public abstract class JetTypeJetSignatureReader extends JetSignatureExceptionsAd
         
         this.classDescriptor = null;
         if (!forceReal) {
-            classDescriptor = javaSemanticServices.getTypeTransformer().getKotlinAnalog(ourName);
+            classDescriptor = javaSemanticServices.getTypeTransformer().getKotlinAnalog(ourName, JavaTypeTransformer.TypeUsage.MEMBER_SIGNATURE_INVARIANT);
         }
 
         if (classDescriptor == null) {
diff --git a/compiler/frontend/src/jet/Iterables.jet b/compiler/frontend/src/jet/Iterables.jet
index 901636139f4..8f3f685a4bb 100644
--- a/compiler/frontend/src/jet/Iterables.jet
+++ b/compiler/frontend/src/jet/Iterables.jet
@@ -4,6 +4,10 @@ public trait Iterable<out T> {
   public fun iterator() : Iterator<T>
 }
 
+public trait MutableIterable<out T> : Iterable<T> {
+  override fun iterator() : MutableIterator<T>
+}
+
 public trait ByteIterable : Iterable<Byte> {
   public override fun iterator() : ByteIterator
 }
diff --git a/compiler/frontend/src/jet/Iterators.jet b/compiler/frontend/src/jet/Iterators.jet
index 365b842c3ac..717504c7132 100644
--- a/compiler/frontend/src/jet/Iterators.jet
+++ b/compiler/frontend/src/jet/Iterators.jet
@@ -5,6 +5,10 @@ public trait Iterator<out T> {
   public fun hasNext() : Boolean
 }
 
+public trait MutableIterator<out T> : Iterator<T> {
+  public fun remove()
+}
+
 public abstract class ByteIterator() : Iterator<Byte> {
   public abstract open fun nextByte() : Byte
 
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibrary.java b/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibrary.java
index 065f1b9aa02..b35e816202b 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibrary.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibrary.java
@@ -94,6 +94,8 @@ public class JetStandardLibrary {
     private ClassDescriptor arrayClass;
     private ClassDescriptor iterableClass;
     private ClassDescriptor iteratorClass;
+    private ClassDescriptor mutableIterableClass;
+    private ClassDescriptor mutableIteratorClass;
     private ClassDescriptor comparableClass;
     private ClassDescriptor throwableClass;
     private ClassDescriptor enumClass;
@@ -170,6 +172,8 @@ public class JetStandardLibrary {
 
             this.iterableClass = (ClassDescriptor) libraryScope.getClassifier(Name.identifier("Iterable"));
             this.iteratorClass = (ClassDescriptor) libraryScope.getClassifier(Name.identifier("Iterator"));
+            this.mutableIterableClass = (ClassDescriptor) libraryScope.getClassifier(Name.identifier("MutableIterable"));
+            this.mutableIteratorClass = (ClassDescriptor) libraryScope.getClassifier(Name.identifier("MutableIterator"));
             this.comparableClass = (ClassDescriptor) libraryScope.getClassifier(Name.identifier("Comparable"));
 
             this.stringType = new JetTypeImpl(getString());
@@ -213,6 +217,8 @@ public class JetStandardLibrary {
         classDescriptors.add(throwableClass);
         classDescriptors.add(iterableClass);
         classDescriptors.add(iteratorClass);
+        classDescriptors.add(mutableIterableClass);
+        classDescriptors.add(mutableIteratorClass);
         classDescriptors.add(comparableClass);
         classDescriptors.add(enumClass);
 
@@ -301,6 +307,18 @@ public class JetStandardLibrary {
         return iteratorClass;
     }
 
+    @NotNull
+    public ClassDescriptor getMutableIterable() {
+        initStdClasses();
+        return mutableIterableClass;
+    }
+
+    @NotNull
+    public ClassDescriptor getMutableIterator() {
+        initStdClasses();
+        return mutableIteratorClass;
+    }
+
     @NotNull
     public ClassDescriptor getComparable() {
         initStdClasses();
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibraryNames.java b/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibraryNames.java
index 3034b3ac416..50ddc903adc 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibraryNames.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/types/lang/JetStandardLibraryNames.java
@@ -41,6 +41,8 @@ public class JetStandardLibraryNames {
     public static final ClassName COMPARABLE = classIn("Comparable", 1);
     public static final ClassName ITERABLE = classIn("Iterable", 1);
     public static final ClassName ITERATOR = classIn("Iterator", 1);
+    public static final ClassName MUTABLE_ITERABLE = classIn("MutableIterable", 1);
+    public static final ClassName MUTABLE_ITERATOR = classIn("MutableIterator", 1);
     public static final ClassName NOTHING = classIn("Nothing", 0);
     public static final ClassName STRING = classIn("String", 0);
     public static final ClassName CHAR_SEQUENCE = classIn("CharSequence", 0);
diff --git a/compiler/testData/builtin-classes.txt b/compiler/testData/builtin-classes.txt
index 4dc04ec2196..c55c686c89f 100644
--- a/compiler/testData/builtin-classes.txt
+++ b/compiler/testData/builtin-classes.txt
@@ -832,6 +832,14 @@ public final class jet.LongRange : jet.Range<jet.Long>, jet.LongIterable {
         public final val EMPTY: jet.LongRange
     }
 }
+public abstract trait jet.MutableIterable</*0*/ out T : jet.Any?> : jet.Iterable<T> {
+    public abstract override /*1*/ fun iterator(): jet.MutableIterator<T>
+}
+public abstract trait jet.MutableIterator</*0*/ out T : jet.Any?> : jet.Iterator<T> {
+    public abstract override /*1*/ fun hasNext(): jet.Boolean
+    public abstract override /*1*/ fun next(): T
+    public abstract fun remove(): jet.Tuple0
+}
 public final class jet.Nothing {
     private final /*constructor*/ fun <init>(): jet.Nothing
 }
diff --git a/compiler/testData/diagnostics/tests/j+k/mutableIterator.kt b/compiler/testData/diagnostics/tests/j+k/mutableIterator.kt
new file mode 100644
index 00000000000..6cba8d1b63a
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/j+k/mutableIterator.kt
@@ -0,0 +1,29 @@
+//FILE:a/JC.java
+package a;
+
+import java.util.Iterator;
+
+public interface JC<T> {
+    public Iterator<T> getIterator();
+
+    public void setIterator(Iterator<T> iterator);
+
+    public Iterable<T> getIterable();
+
+    public void setIterable(Iterable<T> iterable);
+}
+
+//FILE:n.kt
+package n
+
+import a.JC
+
+fun foo(c: JC<Int>, iterator: Iterator<Int>, iterable: Iterable<Int>) {
+    val mutableIterator: MutableIterator<Int>? = c.getIterator()
+    c.setIterator(mutableIterator)
+    c.setIterator(iterator)
+
+    val mutableIterable: MutableIterable<Int>? = c.getIterable()
+    c.setIterable(mutableIterable)
+    c.setIterable(iterable)
+}
\ No newline at end of file
diff --git a/compiler/testData/loadJava/InnerClassesInGeneric.kt b/compiler/testData/loadJava/InnerClassesInGeneric.kt
index 659635577d5..3cf9685624a 100644
--- a/compiler/testData/loadJava/InnerClassesInGeneric.kt
+++ b/compiler/testData/loadJava/InnerClassesInGeneric.kt
@@ -5,7 +5,7 @@ public open class InnerClassesInGeneric<P, Q>() : java.lang.Object() {
     }
     
     public open class Inner2() : Inner() {
-        public open fun iterator() : jet.Iterator<P>? {
+        public open fun iterator() : jet.MutableIterator<P>? {
             throw UnsupportedOperationException()
         }
     }
diff --git a/compiler/testData/loadJava/InnerClassesInGeneric.txt b/compiler/testData/loadJava/InnerClassesInGeneric.txt
index 677c76fc7d2..e67437fc583 100644
--- a/compiler/testData/loadJava/InnerClassesInGeneric.txt
+++ b/compiler/testData/loadJava/InnerClassesInGeneric.txt
@@ -7,6 +7,6 @@ public open class test.InnerClassesInGeneric</*0*/ P : jet.Any?, /*1*/ Q : jet.A
     }
     public open class test.InnerClassesInGeneric.Inner2 : test.InnerClassesInGeneric.Inner {
         public final /*constructor*/ fun <init>(): test.InnerClassesInGeneric.Inner2
-        public open fun iterator(): jet.Iterator<P>?
+        public open fun iterator(): jet.MutableIterator<P>?
     }
 }
diff --git a/compiler/testData/loadJava/library/LoadIterable.java b/compiler/testData/loadJava/library/LoadIterable.java
new file mode 100644
index 00000000000..ad0c98b69e1
--- /dev/null
+++ b/compiler/testData/loadJava/library/LoadIterable.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2010-2012 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 test;
+
+public interface LoadIterable<T> {
+    public Iterable<T> getIterable();
+    public void setIterable(Iterable<T> Iterable);
+}
diff --git a/compiler/testData/loadJava/library/LoadIterable.kt b/compiler/testData/loadJava/library/LoadIterable.kt
new file mode 100644
index 00000000000..22e4b3ea2f8
--- /dev/null
+++ b/compiler/testData/loadJava/library/LoadIterable.kt
@@ -0,0 +1,6 @@
+package test
+
+public trait LoadIterable<T> : java.lang.Object {
+    public fun getIterable(): MutableIterable<T>?
+    public fun setIterable(p0: Iterable<T>?)
+}
diff --git a/compiler/testData/loadJava/library/LoadIterable.txt b/compiler/testData/loadJava/library/LoadIterable.txt
new file mode 100644
index 00000000000..8dd05db16d8
--- /dev/null
+++ b/compiler/testData/loadJava/library/LoadIterable.txt
@@ -0,0 +1,6 @@
+namespace test
+
+public abstract trait test.LoadIterable</*0*/ T : jet.Any?> : java.lang.Object {
+    public abstract fun getIterable(): jet.MutableIterable<T>?
+    public abstract fun setIterable(/*0*/ p0: jet.Iterable<T>?): jet.Tuple0
+}
diff --git a/compiler/testData/loadJava/library/LoadIterator.java b/compiler/testData/loadJava/library/LoadIterator.java
new file mode 100644
index 00000000000..2c262fa0f49
--- /dev/null
+++ b/compiler/testData/loadJava/library/LoadIterator.java
@@ -0,0 +1,8 @@
+package test;
+
+import java.util.Iterator;
+
+public interface LoadIterator<T> {
+    public Iterator<T> getIterator();
+    public void setIterator(Iterator<T> iterator);
+}
diff --git a/compiler/testData/loadJava/library/LoadIterator.kt b/compiler/testData/loadJava/library/LoadIterator.kt
new file mode 100644
index 00000000000..d43c39e15b9
--- /dev/null
+++ b/compiler/testData/loadJava/library/LoadIterator.kt
@@ -0,0 +1,6 @@
+package test
+
+public trait LoadIterator<T> : java.lang.Object {
+    public fun getIterator(): MutableIterator<T>?
+    public fun setIterator(p0: Iterator<T>?)
+}
diff --git a/compiler/testData/loadJava/library/LoadIterator.txt b/compiler/testData/loadJava/library/LoadIterator.txt
new file mode 100644
index 00000000000..c75bdc8da61
--- /dev/null
+++ b/compiler/testData/loadJava/library/LoadIterator.txt
@@ -0,0 +1,6 @@
+namespace test
+
+public abstract trait test.LoadIterator</*0*/ T : jet.Any?> : java.lang.Object {
+    public abstract fun getIterator(): jet.MutableIterator<T>?
+    public abstract fun setIterator(/*0*/ p0: jet.Iterator<T>?): jet.Tuple0
+}
diff --git a/compiler/testData/loadJava/modality/ModalityOfFakeOverrides.txt b/compiler/testData/loadJava/modality/ModalityOfFakeOverrides.txt
index efec7ae1889..224a5da6be8 100644
--- a/compiler/testData/loadJava/modality/ModalityOfFakeOverrides.txt
+++ b/compiler/testData/loadJava/modality/ModalityOfFakeOverrides.txt
@@ -12,7 +12,7 @@ public open class test.ModalityOfFakeOverrides : java.util.AbstractList<jet.Stri
     public open override /*1*/ fun get(/*0*/ p0: jet.Int): jet.String?
     public open override /*1*/ fun indexOf(/*0*/ p0: jet.Any?): jet.Int
     public open override /*1*/ fun isEmpty(): jet.Boolean
-    public open override /*1*/ fun iterator(): jet.Iterator<jet.String>?
+    public open override /*1*/ fun iterator(): jet.MutableIterator<jet.String>?
     public open override /*1*/ fun lastIndexOf(/*0*/ p0: jet.Any?): jet.Int
     public open override /*1*/ fun listIterator(): java.util.ListIterator<jet.String>?
     public open override /*1*/ fun listIterator(/*0*/ p0: jet.Int): java.util.ListIterator<jet.String>?
diff --git a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
index 81a90ea22cb..baefd98e7f1 100644
--- a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
@@ -1706,6 +1706,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/j+k/kt2394.kt");
             }
             
+            @TestMetadata("mutableIterator.kt")
+            public void testMutableIterator() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/j+k/mutableIterator.kt");
+            }
+            
             @TestMetadata("OverrideVararg.kt")
             public void testOverrideVararg() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/j+k/OverrideVararg.kt");
diff --git a/compiler/tests/org/jetbrains/jet/jvm/compiler/LoadJavaTestGenerated.java b/compiler/tests/org/jetbrains/jet/jvm/compiler/LoadJavaTestGenerated.java
index f01eb4fddad..a06b836b460 100644
--- a/compiler/tests/org/jetbrains/jet/jvm/compiler/LoadJavaTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/jvm/compiler/LoadJavaTestGenerated.java
@@ -15,12 +15,15 @@
  */
 package org.jetbrains.jet.jvm.compiler;
 
+import junit.framework.Assert;
 import junit.framework.Test;
 import junit.framework.TestSuite;
+
+import java.io.File;
 import org.jetbrains.jet.JetTestUtils;
 import org.jetbrains.jet.test.TestMetadata;
 
-import java.io.File;
+import org.jetbrains.jet.jvm.compiler.AbstractLoadJavaTest;
 
 /** This class is generated by {@link org.jetbrains.jet.jvm.compiler.AbstractLoadJavaTest}. DO NOT MODIFY MANUALLY */
 @TestMetadata("compiler/testData/loadJava")
@@ -370,6 +373,24 @@ public class LoadJavaTestGenerated extends AbstractLoadJavaTest {
         }
     }
     
+    @TestMetadata("compiler/testData/loadJava/library")
+    public static class Library extends AbstractLoadJavaTest {
+        public void testAllFilesPresentInLibrary() throws Exception {
+            JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.jvm.compiler.AbstractLoadJavaTest", new File("compiler/testData/loadJava/library"), "java", false);
+        }
+        
+        @TestMetadata("LoadIterable.java")
+        public void testLoadIterable() throws Exception {
+            doTest("compiler/testData/loadJava/library/LoadIterable.java");
+        }
+        
+        @TestMetadata("LoadIterator.java")
+        public void testLoadIterator() throws Exception {
+            doTest("compiler/testData/loadJava/library/LoadIterator.java");
+        }
+        
+    }
+    
     @TestMetadata("compiler/testData/loadJava/modality")
     public static class Modality extends AbstractLoadJavaTest {
         public void testAllFilesPresentInModality() throws Exception {
@@ -431,6 +452,7 @@ public class LoadJavaTestGenerated extends AbstractLoadJavaTest {
         suite.addTestSuite(Constructor.class);
         suite.addTestSuite(JavaBean.class);
         suite.addTest(KotlinSignature.innerSuite());
+        suite.addTestSuite(Library.class);
         suite.addTestSuite(Modality.class);
         suite.addTestSuite(NotNull.class);
         suite.addTestSuite(Vararg.class);