@given(start_action_messages, message_dicts, message_dicts, integers(min_value=2))
    def test_duplicate_task_level(self, start_message, child1, child2, index):
        parent_level = start_message.task_level.parent().level
        messages = [
            written_from_pmap(
                union(child_message, {
                    TASK_UUID_FIELD: start_message.task_uuid,
                    TASK_LEVEL_FIELD: parent_level.append(index),
                }))
            for child_message in [child1, child2]]
        assume(messages[0] != messages[1])
        self.assertRaises(
            DuplicateChild,
            WrittenAction.from_messages, start_message, messages)
If we try to add a child to an action that has a task level that's the
dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_action.py/WrittenActionTests.test_duplicate_task_level