@Test public void consumeLetterThenDigitSequence() {

    CharacterReader r = new CharacterReader("One12 Two &bar; qux");
    assertEquals("One12", r.consumeLetterThenDigitSequence());
    assertEquals(' ', r.consume());
    assertEquals("Two", r.consumeLetterThenDigitSequence());
    assertEquals(" &bar; qux", r.consumeToEnd());
}