code: def add(self, command, response):
          
          command = re.compile(command)
          self.response_list.append((command, response))
docs: Register a command/response pair.
  
          The command may be either a string (which is then automatically
          compiled into a regular expression), or a pre-compiled regular
          expression object.
  
          If the given response handler is a string, it is sent as the
          response to any command that matches the given regular expression.
          If the given response handler is a function, it is called
          with the command passed as an argument.
  
          :type  command: str|regex
          :param command: A string or a compiled regular expression.
          :type  response: function|str
          :param response: A reponse, or a response handler.