async def METHOD_NAME(alice, alice_ws, realm):
    certif = RealmRoleCertificate.build_realm_root_certif(
        author=alice.device_id, timestamp=DateTime.now(), realm_id=realm
    ).dump_and_sign(alice.signing_key)
    rep = await realm_create(alice_ws, certif)
    assert isinstance(rep, RealmCreateRepAlreadyExists)