assertThat(UPPER_UNDERSCORE.to(UPPER_UNDERSCORE, "FOO")).isEqualTo("FOO");
    assertThat(UPPER_UNDERSCORE.to(UPPER_UNDERSCORE, "FOO_BAR")).isEqualTo("FOO_BAR");
  }

  public void testConverterToForward() {
    assertThat(UPPER_UNDERSCORE.converterTo(UPPER_CAMEL).convert("FOO_BAR")).isEqualTo("FooBar");
    assertThat(UPPER_UNDERSCORE.converterTo(LOWER_CAMEL).convert("FOO_BAR")).isEqualTo("fooBar");

    @Override
    String normalizeWord(String word) {
      return firstCharOnlyToUpper(word);
    }
  },

  /** Java and C++ constant naming convention, e.g., "UPPER_UNDERSCORE". */
  UPPER_UNDERSCORE(CharMatcher.is('_'), "_") {
    @Override
    String normalizeWord(String word) {
      return Ascii.toUpperCase(word);
    }

    @Override
    String convert(CaseFormat format, String s) {

    @Override
    String normalizeWord(String word) {
      return firstCharOnlyToUpper(word);
    }
  },

  /** Java and C++ constant naming convention, e.g., "UPPER_UNDERSCORE". */
  UPPER_UNDERSCORE(CharMatcher.is('_'), "_") {
    @Override
    String normalizeWord(String word) {
      return Ascii.toUpperCase(word);
    }

    @Override
    String convert(CaseFormat format, String s) {