How to use the prefect.Flow function in prefect

def test_containment():
    s = Memory()
    f = Flow("test")
    s.add_flow(f)

    assert True not in s
    assert f not in s
    assert "test" in s
    assert Flow("other") not in s
    assert "other" not in s

def test_two_dependent_tasks():
    """
    x1 -> x2

    Two identical tasks in a row
    """
    f = Flow(name="test")
    f.add_edge(get_task("x1"), get_task("x2"))
    steps = f.generate_local_task_ids(_debug_steps=True)

    # step 1 isn't enough to differentiate the tasks
    assert count_unique_ids(steps[1]) == 1

    # step 2 is able to differentiate them
    assert count_unique_ids(steps[2]) == 2

    # no further processing
    assert steps[2] == steps[3] == steps[4] == steps[5]

def test_deserialize_flow(self):
        f = Flow()
        f.add_task(Task())
        f.add_task(Parameter("x"))

        env = LocalEnvironment()
        serialized = env.serialize_flow_to_bytes(f)
        deserialized = env.deserialize_flow_from_bytes(serialized)

        assert isinstance(deserialized, Flow)
        assert len(deserialized.tasks) == 2
        assert {p.name for p in deserialized.parameters()} == {"x"}

def test_multiple_flows_in_storage():
    s = Bytes()
    f = Flow("test")
    g = Flow("other")
    z = Flow("not")
    s.add_flow(f)
    s.add_flow(g)

    assert "test" in s
    assert "other" in s
    assert "not" not in s

    assert s.get_flow("test") == f
    assert s.get_flow("other") == g

    assert isinstance(s.flows["test"], bytes)
    assert isinstance(s.flows["other"], bytes)

def test_flow_runner_loads_parameters_from_cloud(monkeypatch):

    flow = prefect.Flow(name="test")
    get_flow_run_info = MagicMock(return_value=MagicMock(parameters={"a": 1}))
    set_flow_run_state = MagicMock()
    client = MagicMock(
        get_flow_run_info=get_flow_run_info, set_flow_run_state=set_flow_run_state
    )
    monkeypatch.setattr(
        "prefect.engine.cloud.flow_runner.Client", MagicMock(return_value=client)
    )
    res = CloudFlowRunner(flow=flow).initialize_run(
        state=Pending(), task_states={}, context={}, task_contexts={}, parameters={}
    )

    assert res.context["parameters"]["a"] == 1

def test_no_tasks_returns_empty_dict():
    assert Flow(name="test").generate_local_task_ids() == {}

def test_upload_multiple_flows_to_azure_blob_name(monkeypatch):
    client = MagicMock(upload_blob=MagicMock())
    service = MagicMock(get_blob_client=MagicMock(return_value=client))
    monkeypatch.setattr(
        "prefect.environments.storage.Azure._azure_block_blob_service", service
    )

    storage = Azure(container="container", blob_name="name")

    f1 = Flow("test1")
    f2 = Flow("test2")
    assert storage.add_flow(f1)
    assert storage.add_flow(f2)
    assert storage.build()

    assert service.get_blob_client.call_args[1]["container"] == "container"

def test_environment_execute_calls_callbacks():
    start_func = MagicMock()
    exit_func = MagicMock()

    with tempfile.TemporaryDirectory() as directory:

        @prefect.task
        def add_to_dict():
            with open(path.join(directory, "output"), "w") as tmp:
                tmp.write("success")

        with open(path.join(directory, "flow_env.prefect"), "w+") as env:
            flow = prefect.Flow("test", tasks=[add_to_dict])
            flow_path = path.join(directory, "flow_env.prefect")
            with open(flow_path, "wb") as f:
                cloudpickle.dump(flow, f)

        environment = RemoteEnvironment(on_start=start_func, on_exit=exit_func)
        storage = Docker(registry_url="test")

        environment.execute(storage, flow_path)

        with open(path.join(directory, "output"), "r") as file:
            assert file.read() == "success"

        assert start_func.called
        assert exit_func.called

def test_sqlite_error_results_in_failed_state(self, database):
        with Flow(name="test") as f:
            task = SQLiteQuery(db=database, query="SELECT * FROM FOOBAR")()
        out = f.run()
        assert out.is_failed()
        assert "no such table: FOOBAR" in str(out.result[task].result)

def test_multiple_flows_in_storage():
    s = Memory()
    f = Flow("test")
    g = Flow("other")
    z = Flow("not")
    s.add_flow(f)
    s.add_flow(g)

    assert "test" in s
    assert "other" in s
    assert "not" not in s

    assert s.get_flow("test") is f
    assert s.get_flow("other") is g

    assert s.flows["test"] is f
    assert s.flows["other"] is g