code: def _parse_request_arguments(self, request):
      
      inference_addresses = request.args.get('inference_address').split(',')
      model_names = request.args.get('model_name').split(',')
      model_versions = request.args.get('model_version').split(',')
      model_signatures = request.args.get('model_signature').split(',')
      if len(model_names) != len(inference_addresses):
        raise common_utils.InvalidUserInputError('Every model should have a ' +
                                                  'name and address.')
      return inference_addresses, model_names, model_versions, model_signatures
docs: Parses comma separated request arguments
  
      Args:
        request: A request that should contain 'inference_address', 'model_name',
          'model_version', 'model_signature'.
  
      Returns:
        A tuple of lists for model parameters