def METHOD_NAME():
    now = dt.datetime(2017, 1, 1, 12, 34, 56, tzinfo=pytz.utc)
    grp = stix2.v21.Grouping(
        type="grouping",
        id=GROUPING_ID,
        created=now,
        modified=now,
        name="Harry Potter and the Leet Hackers",
        context="suspicious-activity",
        object_refs=[
            "malware--c8d2fae5-7271-400c-b81d-931a4caf20b9",
            "identity--988145ed-a3b4-4421-b7a7-273376be67ce",
        ],
    )
    assert grp.serialize(pretty=True) == EXPECTED_GROUPING