public abstract boolean compare(A actual, E expected);
@Test
  public void testTransforming_both_compare_nullTransformedValue() {
    assertThat(HYPHENS_MATCH_COLONS.compare("mailing-list", "abcdefg-hij")).isFalse();
    assertThat(HYPHENS_MATCH_COLONS.compare("forum", "abcde:fghij")).isFalse();
    assertThat(HYPHENS_MATCH_COLONS.compare("forum", "abcde-fghij")).isTrue();
  }