+ "0123456789\r\n"
            + "!@#$%^&*()-=_+\t[]{};':\",./<>?\\| ");
  }

  public void testMarkAndReset() throws IOException {
    String string = "abcdefghijklmnopqrstuvwxyz";
    CharSequenceReader reader = new CharSequenceReader(string);
    assertTrue(reader.markSupported());

    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset and read again
    reader.reset();

    final CharSequence seq;

    CharSequenceCharSource(CharSequence seq) {
      this.seq = checkNotNull(seq);
    }

    @Override
    public Reader openStream() {
      return new CharSequenceReader(seq);
    }

    @Override
    public String read() {
      return seq.toString();
    }

    @Override
    public boolean isEmpty() {
      return seq.length() == 0;
    }

    final CharSequence seq;

    CharSequenceCharSource(CharSequence seq) {
      this.seq = checkNotNull(seq);
    }

    @Override
    public Reader openStream() {
      return new CharSequenceReader(seq);
    }

    @Override
    public String read() {
      return seq.toString();
    }

    @Override
    public boolean isEmpty() {
      return seq.length() == 0;
    }