public void testWhitespace() {

    // 4. Whitespace
    matcher = new ApproximateMatcher();
    assertEquals(2, matcher.match(" a_", "_a "));
    matcher.setIgnoreWhitespace(true);
    assertEquals(0, matcher.match(matcher.process(" a_"), matcher.process("_a ")));

    matcher = new ApproximateMatcher();
    assertEquals(1, matcher.match("a b", "ab"));
    matcher.setIgnoreWhitespace(true);
    assertEquals(0, matcher.match(matcher.process("a b"), matcher.process("ab")));

    matcher = new ApproximateMatcher();
    assertEquals(1, matcher.match("ab", "a_b"));
    matcher.setIgnoreWhitespace(true);
    assertEquals(0, matcher.match(matcher.process("ab"), matcher.process("a_b")));
  }