code: def post(self, post_id, fields=None, **params):
  
          
          if fields:
              fields = ",".join(fields)
  
          parameters = {"fields": fields,
                        "access_token": self.key}
          parameters = self.merge_params(parameters, params)
  
          return self.api_call('%s' % post_id, parameters)
docs: :param post_id:
          :param fields:
          :param params:
          :return: