public function removeRole($role)
    {
        if ($this->instance instanceof \Phavour\Session\Storage) {
            if (!$this->hasRole($role)) {
                return false;
            }
            if ($this->instance->isLocked()) {
                $this->instance->unlock();
            }
            $roles = $this->instance->get('roles');
            if (is_array($roles)) {
                $new = array();
                foreach ($roles as $old) {
                    if ($old != $role) {
                        $new[] = $old;
                    }
                }
                $this->instance->set('roles', $new);
            }

            $this->instance->lock();
            return true;
        }

        return false;
    }