code: def set_text(self, text):
          
          log = logging.getLogger(self.cls_logger + '.set_text')
          if not isinstance(text, basestring):
              msg = 'text arg must be a string'
              log.error(msg)
              raise ValueError(msg)
          self.payload['text'] = text
          log.debug('Set message text to: {t}'.format(t=text))
docs: Sets the text attribute of the payload
  
          :param text: (str) Text of the message
          :return: None