assertEqualCharNodes(traverser.breadthFirst('b'), "bcda");
    assertEqualCharNodes(traverser.breadthFirst('c'), "cdab");
    assertEqualCharNodes(traverser.breadthFirst('d'), "dabc");
  }

  @Test
  public void forGraph_breadthFirstIterable_cycle() {
    Traverser<Character> traverser = Traverser.forGraph(CYCLE_GRAPH);
    assertEqualCharNodes(traverser.breadthFirst(charactersOf("a")), "abcd");

}

type LinesTest struct {
	a string
	b []string
}

var linesTests = []LinesTest{
	{a: "abc\nabc\n", b: []string{"abc\n", "abc\n"}},
	{a: "abc\r\nabc", b: []string{"abc\r\n", "abc"}},
	{a: "abc\r\n", b: []string{"abc\r\n"}},
	{a: "\nabc", b: []string{"\n", "abc"}},
	{a: "\nabc\n\n", b: []string{"\n", "abc\n", "\n"}},
}

func TestLines(t *testing.T) {
	for _, s := range linesTests {

      MockResponse
        .Builder()
        .body("abc")
        .build(),
    )
    val call =
      client.newCallWithListener(
        Request
          .Builder()
          .url(server.url("/"))
          .build(),
      )
    val response = call.execute()
    assertThat(response.code).isEqualTo(200)
    assertThat(response.body.string()).isEqualTo("abc")
    response.body.close()

		{"/abc/", "/abc"},

		// Remove doubled slash
		{"abc//def//ghi", "abc/def/ghi"},
		{"//abc", "/abc"},
		{"///abc", "/abc"},
		{"//abc//", "/abc"},
		{"abc//", "abc"},

		// Remove . elements
		{"abc/./def", "abc/def"},
		{"/./abc/def", "/abc/def"},
		{"abc/.", "abc"},

		// Remove .. elements
		{"abc/def/ghi/../jkl", "abc/def/jkl"},
		{"abc/def/../ghi/../jkl", "abc/jkl"},
		{"abc/def/..", "abc"},

        assertEquals("", StringUtil.substringToLast("abc", "c"));
        assertEquals("c", StringUtil.substringToLast("abc", "b"));
        assertEquals("c", StringUtil.substringToLast("abcbc", "b"));
        assertEquals("abc", StringUtil.substringToLast("abc", ""));
        assertEquals("abc", StringUtil.substringToLast("abc", null));
        assertEquals("abc", StringUtil.substringToLast("abc", "dddd"));
    }

    /**

        FullWidthToHalfWidthAlphabetNormalizer normalizer = new FullWidthToHalfWidthAlphabetNormalizer();

        String result = normalizer.normalize("ａｂｃ あいう 123", "field");

        assertEquals("abc あいう 123", result);
    }

    @Test
    public void test_fullWidthSpacePreserved() throws Exception {

		wantRes string
		wantKey string
		wantVal string
		ok      bool
	}{
		{"6 k=v\n\n", "\n", "k", "v", true},
		{"19 path=/etc/hosts\n", "", "path", "/etc/hosts", true},
		{"210 path=" + longName + "\nabc", "abc", "path", longName, true},
		{"110 path=" + medName + "\n", "", "path", medName, true},
		{"9 foo=ba\n", "", "foo", "ba", true},
		{"11 foo=bar\n\x00", "\x00", "foo", "bar", true},

    assertEquals(java.util.Optional.of("abc"), Optional.toJavaUtil(Optional.of("abc")));
  }

  public void testToJavaUtil_instance() {
    assertEquals(java.util.Optional.empty(), Optional.absent().toJavaUtil());
    assertEquals(java.util.Optional.of("abc"), Optional.of("abc").toJavaUtil());
  }

  @SuppressWarnings("NullOptional")
  public void testFromJavaUtil() {

        String result = chain.normalize("ａｂｃ", "field");

        assertEquals("abc", result);
    }

    @Test
    public void test_multipleNormalizers() throws Exception {
        NormalizerChain chain = new NormalizerChain();
        chain.add(new FullWidthToHalfWidthAlphabetNormalizer());
        chain.add(new HankakuKanaToZenkakuKana());

        String result = chain.normalize("ａｂｃ ｶﾞ", "field");

      MockResponse
        .Builder()
        .body("abc")
        .doNotReadRequestBody()
        .build(),
    )

    val call =
      client.newCall(
        Request(
          url = server.url("/"),
          body = SlowRequestBody,
        ),
      )

    call.execute().use { response ->
      assertThat(response.body.string()).isEqualTo("abc")
    }