return new CharSource() {
      @Override
      public Reader openStream() {
        return new StringReader(text);
      }
    };
  }

  public void testSkip() throws Exception {
    String begin = "abcde";
    String end = "fghij";
    Reader joinedReader = CharSource.concat(newCharSource(begin), newCharSource(end)).openStream();

    String expected = begin + end;
    assertEquals(expected.charAt(0), joinedReader.read());

  }

  public void testConcat() throws IOException {
    CharSource c1 = CharSource.wrap("abc");
    CharSource c2 = CharSource.wrap("");
    CharSource c3 = CharSource.wrap("de");

    String expected = "abcde";

    assertEquals(expected, CharSource.concat(ImmutableList.of(c1, c2, c3)).read());
    assertEquals(expected, CharSource.concat(c1, c2, c3).read());

    assertEqualCharNodes(traverser.breadthFirst(charactersOf("bc")), "bcda");
  }

  @Test
  public void forGraph_breadthFirst_twoCycles() {
    Traverser<Character> traverser = Traverser.forGraph(TWO_CYCLES_GRAPH);
    assertEqualCharNodes(traverser.breadthFirst('a'), "abcd");
    assertEqualCharNodes(traverser.breadthFirst('b'), "bcda");
    assertEqualCharNodes(traverser.breadthFirst('c'), "cdab");

    assertEquals("", Strings.commonPrefix("abc", ""));
    assertEquals("", Strings.commonPrefix("", "abc"));
    assertEquals("", Strings.commonPrefix("abcde", "xyz"));
    assertEquals("", Strings.commonPrefix("xyz", "abcde"));
    assertEquals("", Strings.commonPrefix("xyz", "abcxyz"));
    assertEquals("a", Strings.commonPrefix("abc", "aaaaa"));
    assertEquals("aa", Strings.commonPrefix("aa", "aaaaa"));

    builder.append("C");
    assertEquals("C", iterator.next());
    assertFalse(iterator.hasNext());
  }

  public void testFixedLengthSimpleSplit() {
    String simple = "abcde";
    Iterable<String> letters = Splitter.fixedLength(2).split(simple);
    assertThat(letters).containsExactly("ab", "cd", "e").inOrder();
  }

  public void testFixedLengthSplitEqualChunkLength() {

    return onPatternInternal(Platform.compilePattern(separatorPattern));
  }

  /**
   * Returns a splitter that divides strings into pieces of the given length. For example, {@code
   * Splitter.fixedLength(2).split("abcde")} returns an iterable containing {@code ["ab", "cd",
   * "e"]}. The last piece can be smaller than {@code length} but will never be empty.
   *

    //     the smaller of these blocks with the far end of the other one. That leaves us with a
    //     smaller version of the same problem.
    //     Say we are rotating abcdefgh by 5. We start with abcde|fgh. The smaller block is [fgh]:
    //     [abc]de|[fgh] -> [fgh]de|[abc]. Now [fgh] is in the right place, but we need to swap [de]
    //     with [abc]: fgh[de]|a[bc] -> fgh[bc]|a[de]. Now we need to swap [a] with [bc]:

    builder.append("C");
    assertEquals("C", iterator.next());
    assertFalse(iterator.hasNext());
  }

  public void testFixedLengthSimpleSplit() {
    String simple = "abcde";
    Iterable<String> letters = Splitter.fixedLength(2).split(simple);
    assertThat(letters).containsExactly("ab", "cd", "e").inOrder();
  }

  public void testFixedLengthSplitEqualChunkLength() {

    return onPatternInternal(Platform.compilePattern(separatorPattern));
  }

  /**
   * Returns a splitter that divides strings into pieces of the given length. For example, {@code
   * Splitter.fixedLength(2).split("abcde")} returns an iterable containing {@code ["ab", "cd",
   * "e"]}. The last piece can be smaller than {@code length} but will never be empty.
   *

    assertEquals("", Strings.commonPrefix("abc", ""));
    assertEquals("", Strings.commonPrefix("", "abc"));
    assertEquals("", Strings.commonPrefix("abcde", "xyz"));
    assertEquals("", Strings.commonPrefix("xyz", "abcde"));
    assertEquals("", Strings.commonPrefix("xyz", "abcxyz"));
    assertEquals("a", Strings.commonPrefix("abc", "aaaaa"));
    assertEquals("aa", Strings.commonPrefix("aa", "aaaaa"));