V v = entry.getValue();

      Set<V> values = multimap().get(k);
      Set<V> expectedValues = copyToSet(values);

      assertFalse(multimap().put(k, v));
      assertEquals(expectedValues, values);
      assertGet(k, expectedValues);
    }
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testPutDuplicateValue_null() {
    initMultimapWithNullValue();

    for (K k : sampleKeys()) {
      resetContainer();

      Set<V> expectedValues = copyToSet(multimap().get(k));

      multimap().putAll(k, valuesToPut);
      expectedValues.addAll(valuesToPut);

      assertGet(k, expectedValues);
    }
  }

    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    multimap().clear();
    assertCleared();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    multimap().clear();
    assertCleared();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemove() {
    assertContentsInOrder(multimap().asMap().remove(k0()), v0());
    assertGet(k0());
    assertEquals(getNumElements() - 1, multimap().size());
  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_PUT)
  public void testAsMapEntrySetReflectsPutSameKey() {

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemove() {
    assertContentsInOrder(multimap().asMap().remove(k0()), v0());
    assertGet(k0());
    assertEquals(getNumElements() - 1, multimap().size());
  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_PUT)
  public void testAsMapEntrySetReflectsPutSameKey() {

  TF_Operation* a = Placeholder(graph, s, "A");
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  TF_Operation* b = Placeholder(graph, s, "B");
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  TF_Operation* two = ScalarConst(2, graph, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  TF_Operation* plus2 = Add(a, two, graph, s, "plus2");
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  ASSERT_EQ(errors::OK, s.code()) << s.message();
  if (isa<TracingOperation>(check_numerics_op.get())) {
    s = dyn_cast<TracingOperation>(check_numerics_op.get())
            ->SetOpName("check_numerics");
    ASSERT_EQ(errors::OK, s.code()) << s.message();
  }
  s = AddInput(check_numerics_op.get(), t.get(), &forward_op);
  ASSERT_EQ(errors::OK, s.code()) << s.message();

  ASSERT_EQ(TF_OK, TF_GetCode(status.get())) << TF_Message(status.get());

  TF_OutputListSetNumOutputs(mm_outputs, 1, status.get());
  ASSERT_EQ(TF_OK, TF_GetCode(status.get())) << TF_Message(status.get());
  TF_ExecuteOperation(fn_op, 1, &input_t, mm_outputs, status.get());
  ASSERT_EQ(TF_OK, TF_GetCode(status.get())) << TF_Message(status.get());

  ASSERT_EQ(1, TF_OutputListNumOutputs(mm_outputs));

    matmul = TFE_NewOp(ctx, "MatMulFunction", status);
    ASSERT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);
    TFE_OpAddInput(matmul, h0_task0, status);
    ASSERT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);
    TFE_OpAddInput(matmul, has_packed_input ? packed_handle : h1_task2, status);
    ASSERT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);
  } else {