public function isEmailExists( $email, $excludeId = null )
    {
        return $this->isExists( empty( $excludeId ) ? array(
            'email'     => $email,
            'confirmed' => true,
            new Predicate\Operator(
                'state',
                Predicate\Operator::OP_NE,
                Structure::STATE_INACTIVE
            ),
        ) : array(
            'email' => $email,
            new Predicate\Operator(
                'id',
                Predicate\Operator::OP_NE,
                $excludeId
            ),
        ) );
    }