code: @Beta
      public static void checkMatches(String reference, Pattern pattern,
                                      @Nullable Object errorMessage) {
          checkMatches(reference, pattern, String.valueOf(errorMessage), EMPTY_ERROR_MESSAGE_ARGS);
      }
docs: Performs check with the regular expression pattern.
  
  @param reference    reference to check
  @param pattern      the regular expression pattern
  @param errorMessage the exception message to use if the check fails; will
  be converted to a string using {@link String#valueOf(Object)}
  @throws IllegalArgumentException if the {@code reference} doesn't match provided regular expression
  @see Checks#checkMatches(String, java.util.regex.Pattern, String, Object...)