public void testLowerUnderscoreToLowerHyphen() {
    assertThat(LOWER_UNDERSCORE.to(LOWER_HYPHEN, "foo")).isEqualTo("foo");
    assertThat(LOWER_UNDERSCORE.to(LOWER_HYPHEN, "foo_bar")).isEqualTo("foo-bar");
  }

  public void testLowerUnderscoreToLowerUnderscore() {
    assertThat(LOWER_UNDERSCORE.to(LOWER_UNDERSCORE, "foo")).isEqualTo("foo");
    assertThat(LOWER_UNDERSCORE.to(LOWER_UNDERSCORE, "foo_bar")).isEqualTo("foo_bar");
  }

            return key;
        }
        String keyStr = key.toString();
        if (keyStr.indexOf('_') < 0) {
            keyStr = CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, StringUtils.uncapitalize(keyStr));
        } else {
            keyStr = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, keyStr);
        }
        return keyStr;
    }

    @Override
    public int size() {
        return parent.size();
    }

    protected Map<String, Object> toLowerHyphen(final Map<String, Object> source) {
        return source.entrySet()
                .stream()
                .collect(Collectors.toMap(e -> CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, e.getKey()), e -> {
                    final Object value = e.getValue();
                    if (value instanceof Map) {
                        @SuppressWarnings("unchecked")