code: def pb_for_delete(document_path, option):
      
      write_pb = write_pb2.Write(delete=document_path)
      if option is not None:
          option.modify_write(write_pb)
  
      return write_pb
docs: Make a ``Write`` protobuf for ``delete()`` methods.
  
      Args:
          document_path (str): A fully-qualified document path.
          option (optional[~.firestore_v1beta1.client.WriteOption]): A
             write option to make assertions / preconditions on the server
             state of the document before applying changes.
  
      Returns:
          google.cloud.firestore_v1beta1.types.Write: A
          ``Write`` protobuf instance for the ``delete()``.