docs: def prompt(self, prompt_msg=None, newline=False):
          """ Writes prompt message to output stream and
              reads line from standard input stream.
  
              `prompt_msg`
                  Message to write.
              `newline`
                  Append newline character to prompt message before writing.
  
              Return string.
              """
  
          if prompt_msg is not None:
              self.write(prompt_msg, newline)
  
          return self._input.readline().rstrip(os.linesep)