checkNotNull(array);
    checkPositionIndexes(fromIndex, toIndex, array.length);
    for (int i = fromIndex, j = toIndex - 1; i < j; i++, j--) {
      byte tmp = array[i];
      array[i] = array[j];
      array[j] = tmp;
    }
  }

  /**
   * Performs a right rotation of {@code array} of "distance" places, so that the first element is

    assertEquals("txt", Files.getFileExtension("blah..txt"));
    assertEquals("txt", Files.getFileExtension(".blah.txt"));
    assertEquals("txt", Files.getFileExtension("/tmp/blah.txt"));
    assertEquals("gz", Files.getFileExtension("blah.tar.gz"));
    assertEquals("", Files.getFileExtension("/"));
    assertEquals("", Files.getFileExtension("."));

    assertEquals("txt", Files.getFileExtension("blah..txt"));
    assertEquals("txt", Files.getFileExtension(".blah.txt"));
    assertEquals("txt", Files.getFileExtension("/tmp/blah.txt"));
    assertEquals("gz", Files.getFileExtension("blah.tar.gz"));
    assertEquals("", Files.getFileExtension("/"));
    assertEquals("", Files.getFileExtension("."));

   *     encoding.
   */
  final byte[] decodeChecked(CharSequence chars)
      throws DecodingException {
    chars = trimTrailingPadding(chars);
    byte[] tmp = new byte[maxDecodedSize(chars.length())];
    int len = decodeTo(tmp, chars);
    return extract(tmp, len);
  }

  /**
   * Returns an {@code InputStream} that decodes base-encoded input from the specified {@code

    return bitSet(chars.toCharArray());
  }

  @GwtIncompatible // java.util.BitSet
  private static BitSet bitSet(char[] chars) {
    BitSet tmp = new BitSet();
    for (char c : chars) {
      tmp.set(c);
    }
    return tmp;
  }

  @GwtIncompatible // java.util.Random, java.util.BitSet
  public void testSmallCharMatcher() {
    CharMatcher len1 = SmallCharMatcher.from(bitSet("#"), "#");

    return bitSet(chars.toCharArray());
  }

  @GwtIncompatible // java.util.BitSet
  private static BitSet bitSet(char[] chars) {
    BitSet tmp = new BitSet();
    for (char c : chars) {
      tmp.set(c);
    }
    return tmp;
  }

  @GwtIncompatible // java.util.Random, java.util.BitSet
  public void testSmallCharMatcher() {
    CharMatcher len1 = SmallCharMatcher.from(bitSet("#"), "#");

    assertEquals("txt", MoreFiles.getFileExtension(FS.getPath("blah..txt")));
    assertEquals("txt", MoreFiles.getFileExtension(FS.getPath(".blah.txt")));
    assertEquals("txt", MoreFiles.getFileExtension(root().resolve("tmp/blah.txt")));
    assertEquals("gz", MoreFiles.getFileExtension(FS.getPath("blah.tar.gz")));
    assertEquals("", MoreFiles.getFileExtension(root()));
    assertEquals("", MoreFiles.getFileExtension(FS.getPath(".")));

    // returned in the last call to it.next(). Without it, 30 should be the last
    // item returned by the iterator.
    Integer lastItem = 0;
    for (Integer tmp : mmHeap) {
      lastItem = tmp;
    }
    assertEquals((Integer) 30, lastItem);
  }

  /**
   * This tests a special case where removeAt has to trickle an element first down one level from a

    checkNotNull(array);
    checkPositionIndexes(fromIndex, toIndex, array.length);
    for (int i = fromIndex, j = toIndex - 1; i < j; i++, j--) {
      float tmp = array[i];
      array[i] = array[j];
      array[j] = tmp;
    }
  }

  /**
   * Performs a right rotation of {@code array} of "distance" places, so that the first element is

    checkNotNull(array);
    checkPositionIndexes(fromIndex, toIndex, array.length);
    for (int i = fromIndex, j = toIndex - 1; i < j; i++, j--) {
      char tmp = array[i];
      array[i] = array[j];
      array[j] = tmp;
    }
  }

  /**
   * Performs a right rotation of {@code array} of "distance" places, so that the first element is