def METHOD_NAME():
    ds = FieldDataset("node")
    assert ds.size is None
    ds.set_value("air_temperature", [0, 0, 0])
    assert ds.size == 3
    assert_array_equal(ds["air_temperature"], (0, 0, 0))
    assert len(ds) == 1
    assert list(ds) == ["air_temperature"]