framework/rbac/PhpManager.php
public function revoke($role, $userId)
    {
        if (isset($this->assignments[$userId][$role->name])) {
            unset($this->assignments[$userId][$role->name]);
            $this->saveAssignments();
            return true;
        }

        return false;
    }
public function revoke($role, $userId)
    {
        if (isset($this->assignments[$userId][$role->name])) {
            unset($this->assignments[$userId][$role->name]);
            $this->saveAssignments();
            return true;
        }

        return false;
    }
{@inheritdoc}