assertTrue(multimap().putAll(k0(), newArrayList(v3(), v4())::iterator));
    assertGet(k0(), v0(), v3(), v4());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAllNonEmptyCollectionOnPresentKey() {
    assertTrue(multimap().putAll(k0(), newArrayList(v3(), v4())));
    assertGet(k0(), v0(), v3(), v4());
  }

  @MapFeature.Require(SUPPORTS_PUT)

    int size = getNumElements();

    assertGet(k3(), ImmutableList.of());

    assertTrue(multimap().put(k3(), v3()));

    assertGet(k3(), v3());
    assertEquals(size + 1, multimap().size());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutPresent() {
    int size = getNumElements();

    assertGet(k0(), v0());

    assertTrue(multimap().putAll(k0(), newArrayList(v3(), v4())::iterator));
    assertGet(k0(), v0(), v3(), v4());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAllNonEmptyCollectionOnPresentKey() {
    assertTrue(multimap().putAll(k0(), newArrayList(v3(), v4())));
    assertGet(k0(), v0(), v3(), v4());
  }

  @MapFeature.Require(SUPPORTS_PUT)

    assertGet(k0(), ImmutableList.of());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  public void testRemoveNullKeyPresent() {
    initMultimapWithNullKey();

    assertTrue(multimap().remove(null, getValueForNullKey()));

    expectMissing(mapEntry((K) null, getValueForNullKey()));
    assertGet(getKeyForNullValue(), ImmutableList.of());

    assertGet(k0(), ImmutableList.of());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  public void testRemoveNullKeyPresent() {
    initMultimapWithNullKey();

    assertTrue(multimap().remove(null, getValueForNullKey()));

    expectMissing(mapEntry((K) null, getValueForNullKey()));
    assertGet(getKeyForNullValue(), ImmutableList.of());

  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(1, grads.size());
  ASSERT_EQ(func_name_, grads[0].first);
  ASSERT_EQ("MyGrad", grads[0].second);

  // These calls must be noops
  TF_GraphCopyFunction(host_graph_, func_, grad_func, s_);
  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);
  TF_GraphCopyFunction(host_graph_, func_, nullptr, s_);
  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  // Delete the gradient func.

  TF_OperationDescription* desc = TF_NewOperation(graph, "Const", name);
  TF_SetAttrTensor(desc, "value", t, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);
  TF_SetAttrType(desc, "dtype", TF_TensorType(t));
  *op = TF_FinishOperation(desc, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);
  ASSERT_NE(*op, nullptr);
}

TF_Operation* Const(TF_Tensor* t, TF_Graph* graph, TF_Status* s,

     * specified for this filter. The wildcard has no influence on this
     * method as the server should have performed that filtering already. The
     * attributes are asserted here only because server file systems may not
     * support filtering by all attributes (e.g. even though ATTR_DIRECTORY was
     * specified the server may still return objects that are not directories).
     */
    @Override

     * specified for this filter. The wildcard has no influence on this
     * method as the server should have performed that filtering already. The
     * attributes are asserted here only because server file systems may not
     * support filtering by all attributes (e.g. even though ATTR_DIRECTORY was
     * specified the server may still return objects that are not directories).
     */
    @Override