async def METHOD_NAME(backend_asgi_app, alice_ws, bob, alice):
    now = DateTime.now()
    bob_revocation = RevokedUserCertificate(
        author=alice.device_id, timestamp=now, user_id=bob.user_id
    ).dump_and_sign(alice.signing_key)
    rep = await user_revoke(alice_ws, revoked_user_certificate=bob_revocation)
    assert isinstance(rep, UserRevokeRepOk)
    rep = await user_revoke(alice_ws, revoked_user_certificate=bob_revocation)
    assert isinstance(rep, UserRevokeRepAlreadyRevoked)