def METHOD_NAME(self):
    vlans_from_request = [1, 2, 3]
    old_trunked_vlans = [3]  # Vlans from querying the netbox
    allowed_vlans = range(1, 10)
    self.assertEqual(
        filter_vlans(vlans_from_request, old_trunked_vlans, allowed_vlans),
        [1, 2, 3],
    )