def METHOD_NAME(self, *, table):
    with patch("faust.tables.base.current_event") as current_event:
        event = current_event.return_value
        partition = event.message.partition
        table.send_changelog = Mock(name="send_changelog")
        table.data["foo"] = 3
        table._del_key("foo")
        table.send_changelog.asssert_called_once_with(partition, "foo", None)
        assert "foo" not in table.data