How to use the puppetboard.utils.yield_or_stop function in puppetboard

def test_stop_conn_error():
    def my_generator():
        yield 1
        raise ConnectionError
        yield 2
    gen = utils.yield_or_stop(my_generator())
    for val in gen:
        assert 1 == val

def test_iter():
    test_list = (0, 1, 2, 3)

    def my_generator():
        for i in test_list:
            yield i

    gen = utils.yield_or_stop(my_generator())
    assert isinstance(gen, GeneratorType)

    i = 0
    for val in gen:
        assert i == val
        i = i + 1

def test_stop_empty():
    def my_generator():
        yield 1
        raise EmptyResponseError
        yield 2

    gen = utils.yield_or_stop(my_generator())
    for val in gen:
        assert 1 == val

def test_stop_http_error():
    def my_generator():
        yield 1
        raise HTTPError
        yield 2
    gen = utils.yield_or_stop(my_generator())
    for val in gen:
        assert 1 == val

unrep_query = OrOperator()
        unrep_query.add(NullOperator('report_timestamp', True))
        unrep_query.add(LessEqualOperator('report_timestamp', unreported))

        query.add(unrep_query)

    if len(query.operations) == 0:
        query = None

    nodelist = puppetdb.nodes(
        query=query,
        unreported=app.config['UNRESPONSIVE_HOURS'],
        with_status=True,
        with_event_numbers=app.config['WITH_EVENT_NUMBERS'])
    nodes = []
    for node in yield_or_stop(nodelist):
        if status_arg:
            if node.status == status_arg:
                nodes.append(node)
        else:
            nodes.append(node)
    return Response(stream_with_context(
        stream_template('nodes.html',
                        nodes=nodes,
                        envs=envs,
                        current_env=env)))

query.add(EqualsOperator("certname", node_name))
    query.add(report_id_query)

    reports = puppetdb.reports(query=query)

    try:
        report = next(reports)
    except StopIteration:
        abort(404)

    report.version = commonmark.commonmark(report.version)

    return render_template(
        'report.html',
        report=report,
        events=yield_or_stop(report.events()),
        logs=report.logs,
        metrics=report.metrics,
        envs=envs,
        current_env=env)