}

  public void test_useForNull_twice() {
    Joiner j = Joiner.on("x").useForNull("y");
    assertThrows(UnsupportedOperationException.class, () -> j.useForNull("y"));
  }

  public void testMap() {
    MapJoiner j = Joiner.on(';').withKeyValueSeparator(':');
    assertEquals("", j.join(ImmutableMap.of()));
    assertEquals(":", j.join(ImmutableMap.of("", "")));

  string api_def_overwrites = R"(op: <
  graph_op_name: "TestCApi"
  summary: "New summary"
>
)";
  status = TF_NewStatus();
  TF_ApiDefMapPut(api_def_map, api_def_overwrites.c_str(),
                  api_def_overwrites.size(), status);
  EXPECT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);
  TF_DeleteStatus(status);

  string op_name = "TestCApi";
  status = TF_NewStatus();
  auto* api_def_buf =

    ],
    output_dir = "_api/v1/",
    output_files = TENSORFLOW_API_INIT_FILES_V1,
    output_package = "tensorflow._api.v1",
    packages_to_ignore = ["tensorflow.python.framework.test_ops"],
    root_file_name = "v1.py",
    root_init_template = "api_template_v1.__init__.py",
)

generate_apis(
    name = "tf_python_api_gen_v2",
    api_packages_file_name = "api_packages.txt",

	const step = 13
	if r >= 'a' && r <= 'z' {
		return ((r - 'a' + step) % 26) + 'a'
	}
	if r >= 'A' && r <= 'Z' {
		return ((r - 'A' + step) % 26) + 'A'
	}
	return r
}

func TestMap(t *testing.T) {
	// Run a couple of awful growth/shrinkage tests
	a := tenRunes('a')

	// 1.  Grow. This triggers two reallocations in Map.
	maxRune := func(r rune) rune { return unicode.MaxRune }