code: def _delete(self, state=None):
          
          mutation_val = data_v2_pb2.Mutation.DeleteFromRow()
          mutation_pb = data_v2_pb2.Mutation(delete_from_row=mutation_val)
          self._get_mutations(state).append(mutation_pb)
docs: Helper for :meth:`delete`
  
          Adds a delete mutation (for the entire row) to the accumulated
          mutations.
  
          ``state`` is unused by :class:`DirectRow` but is used by
          subclasses.
  
          :type state: bool
          :param state: (Optional) The state that is passed along to
                        :meth:`_get_mutations`.