code: def _parse_json(self, jstring=None):
          
  
          # Argument error checking.
          assert jstring is not None
  
          result = None
  
          try:
              result = json.loads(jstring)
          except (ValueError) as exception:
              msg = 'Unable to convert JSON string to Python data structure.'
              raise APIDataException(exception, jstring, msg)
  
          return result
docs: Parse jstring and return a Python data structure.
  
          'jstring' a string of JSON. May not be None.
  
          Returns a Python data structure.
  
          If jstring couldn't be parsed, raises an APIDataException.