How to use the dagit.app function in dagit

def test_smoke_app():
    repository_container = app.RepositoryContainer(repository=define_example_repository())
    pipeline_run_storage = PipelineRunStorage()
    flask_app = app.create_app(repository_container, pipeline_run_storage)
    client = flask_app.test_client()

    result = client.post('/graphql', data={'query': 'query { pipelines { nodes { name }}}'})

    data = json.loads(result.data.decode('utf-8'))

    assert data == {"data": {"pipelines": {"nodes": [{"name": "pandas_hello_world"}]}}}

def test_smoke_app():
    repository_container = app.RepositoryContainer(repository=define_example_repository())
    pipeline_run_storage = PipelineRunStorage()
    flask_app = app.create_app(repository_container, pipeline_run_storage)
    client = flask_app.test_client()

    result = client.post('/graphql', data={'query': 'query { pipelines { nodes { name }}}'})

    data = json.loads(result.data.decode('utf-8'))

    assert len(data['data']['pipelines']['nodes']) == 2

    assert set([node_data['name'] for node_data in data['data']['pipelines']['nodes']]) == set(
        ['pandas_hello_world', 'pandas_hello_world_fails']
    )

def test_smoke_app():
    repository_container = app.RepositoryContainer(repository=define_example_repository())
    pipeline_run_storage = PipelineRunStorage()
    flask_app = app.create_app(repository_container, pipeline_run_storage)
    client = flask_app.test_client()

    result = client.post('/graphql', data={'query': 'query { pipelines { nodes { name }}}'})

    data = json.loads(result.data.decode('utf-8'))

    assert data == {"data": {"pipelines": {"nodes": [{"name": "pandas_hello_world"}]}}}

def test_smoke_app():
    repository_container = app.RepositoryContainer(repository=define_example_repository())
    pipeline_run_storage = PipelineRunStorage()
    flask_app = app.create_app(repository_container, pipeline_run_storage)
    client = flask_app.test_client()

    result = client.post('/graphql', data={'query': 'query { pipelines { nodes { name }}}'})

    data = json.loads(result.data.decode('utf-8'))

    assert len(data['data']['pipelines']['nodes']) == 2

    assert set([node_data['name'] for node_data in data['data']['pipelines']['nodes']]) == set(
        ['pandas_hello_world', 'pandas_hello_world_fails']
    )

def test_smoke_app():
    flask_app = app.create_app(
        ExecutionTargetHandle.for_repo_module(
            module_name='dagster_examples.intro_tutorial.repos', fn_name='define_repo'
        ),
        DagsterInstance.ephemeral(),
    )
    client = flask_app.test_client()

    result = client.post('/graphql', data={'query': 'query { pipelines { nodes { name }}}'})
    data = json.loads(result.data.decode('utf-8'))
    assert len(data['data']['pipelines']['nodes']) == 2
    assert {node_data['name'] for node_data in data['data']['pipelines']['nodes']} == set(
        ['hello_cereal_pipeline', 'complex_pipeline']
    )

    result = client.get('/graphql')
    assert result.status_code == 400