void CreateMembership()
    {
        // Got new room, now create membership.
        var newMembership = new Membership(testRoom, person);

        // Commit to Spark.
        StartCoroutine(newMembership.Commit(error =>
        {
            // Failed!
            Fail(error.Message);
        }, commited =>
        {
            // Seems to have worked, but we don't know for sure yet.
            membership = newMembership;
            GetMembership();
        }));
    }