private string GetProviderId(FirebaseAuthType authType)
        {
            switch (authType)
            {
            case FirebaseAuthType.Facebook:
            case FirebaseAuthType.Google:
            case FirebaseAuthType.Github:
            case FirebaseAuthType.Twitter:
                return(authType.ToString());

            case FirebaseAuthType.EmailAndPassword:
                throw new InvalidOperationException("Email auth type cannot be used like this. Use methods specific to email & password authentication.");

            default:
                throw new NotImplementedException("");
            }
        }