def METHOD_NAME():
    ns_builder = NWBNamespaceBuilder(
        doc="An NWB test extension",
        name="ndx-testextension",
        version="0.1.0",
        author="PyNWB Test File Generator",
        contact="my_email@example.com",
    )
    ns_builder.include_type('TimeSeries', namespace='core')
    tetrode_series = NWBGroupSpec(
        neurodata_type_def='TimeSeriesWithID',
        neurodata_type_inc='TimeSeries',
        doc=('An extension of TimeSeries to include an ID.'),
        attributes=[
            NWBAttributeSpec(
                name='id',
                doc='The time series ID.',
                dtype='int32'
            ),
        ],
    )
    new_data_types = [tetrode_series]
    # export the spec to yaml files in the current directory
    export_spec(ns_builder, new_data_types, output_dir=".")
    nwbfile = NWBFile(session_description='ADDME',
                      identifier='ADDME',
                      session_start_time=datetime.now().astimezone())
    load_namespaces("ndx-testextension.namespace.yaml")  # load from the current directory
    TimeSeriesWithID = get_class("TimeSeriesWithID", "ndx-testextension")
    ts = TimeSeriesWithID(
        name="test_ts",
        data=[1., 2., 3.],
        description="ADDME",
        unit="ADDME",
        rate=1.,
        id=1,
    )
    nwbfile.add_acquisition(ts)
    test_name = 'nwbfile_with_extension'
    _write(test_name, nwbfile)