return JavaLowerCase.INSTANCE;
  }

  /**
   * Determines whether a character is an ISO control character as specified by {@link
   * Character#isISOControl(char)}.
   *
   * <p>All ISO control codes are on the BMP and thus supported by this API.
   *
   * @since 19.0 (since 1.0 as constant {@code JAVA_ISO_CONTROL})
   */
  public static CharMatcher javaIsoControl() {
    return JavaIsoControl.INSTANCE;
  }

    return JavaLowerCase.INSTANCE;
  }

  /**
   * Determines whether a character is an ISO control character as specified by {@link
   * Character#isISOControl(char)}.
   *
   * <p>All ISO control codes are on the BMP and thus supported by this API.
   *
   * @since 19.0 (since 1.0 as constant {@code JAVA_ISO_CONTROL})
   */
  public static CharMatcher javaIsoControl() {
    return JavaIsoControl.INSTANCE;
  }

        } else if (obj instanceof Boolean) {
            buf.append(obj.toString());
        } else if (obj instanceof Date) {
            final SimpleDateFormat sdf = new SimpleDateFormat(CoreLibConstants.DATE_FORMAT_ISO_8601_EXTEND, Locale.ROOT);
            buf.append('\"').append(StringEscapeUtils.escapeJson(sdf.format(obj))).append('\"');
        } else {