code: public void expectRegex(String name, Pattern pattern) {
          expectRegex(name, pattern, messages.get(Validation.REGEX_KEY.name(), name));
      }
docs: Validates a field by a given regular expression pattern
  
  It is required to pass a pre-compiled pattern, e.g.
  Pattern pattern = Pattern.compile("[a-Z,0-9]")
  
  @param name The field to check
  @param pattern The pre-compiled pattern