docs: def __write_constant_class(self):
          """
          Inserts new and replaces old (if any) constant declaration statements in the class that acts like a namespace
          for constants.
          """
          helper = ConstantClass(self._class_name, self._io)
  
          content = helper.source_with_constants(self._constants)
  
          Util.write_two_phases(helper.file_name(), content, self._io)