code: def _cancel_http(api_request, operation_name):
      
      path = "operations/{}:cancel".format(operation_name)
      api_request(method="POST", path=path)
docs: Cancel an operation using a JSON/HTTP client.
  
      Args:
          api_request (Callable): A callable used to make an API request. This
              should generally be
              :meth:`google.cloud._http.Connection.api_request`.
          operation_name (str): The name of the operation.