docs: def strip_prompt(self, a_string):
          """Strip the trailing router prompt from the output."""
          expect_string = r"^(OK|ERROR|Command not recognized\.)$"
          response_list = a_string.split(self.RESPONSE_RETURN)
          last_line = response_list[-1]
          if re.search(expect_string, last_line):
              return self.RESPONSE_RETURN.join(response_list[:-1])
          else:
              return a_string