code: def _validate_response(self, response):
          
          if response.text == "Unknown symbol":
              raise IEXQueryError()
          try:
              json_response = response.json(
                  parse_int=self.json_parse_int,
                  parse_float=self.json_parse_float)
              if "Error Message" in json_response:
                  raise IEXQueryError()
          except ValueError:
              raise IEXQueryError()
          return json_response
docs: Ensures response from IEX server is valid.
  
          Parameters
          ----------
          response: requests.response
              A requests.response object
  
          Returns
          -------
          response: Parsed JSON
              A json-formatted response
  
          Raises
          ------
          ValueError
              If a single Share symbol is invalid
          IEXQueryError
              If the JSON response is empty or throws an error