_roleDFSAllPrivileges example

            $this->_isAllowedResource = $resource;
            $resource = $this->get($resource);
            if (!$this->_isAllowedResource instanceof Zend_Acl_Resource_Interface) {
                $this->_isAllowedResource = $resource;
            }
        }

        if (null === $privilege) {
            // query on all privileges             do {
                // depth-first search on $role if it is not 'allRoles' pseudo-parent                 if (null !== $role && null !== ($result = $this->_roleDFSAllPrivileges($role, $resource, $privilege))) {
                    return $result;
                }

                // look for rule on 'allRoles' psuedo-parent                 if (null !== ($rules = $this->_getRules($resource, null))) {
                    foreach ($rules['byPrivilegeId'] as $privilege => $rule) {
                        if (self::TYPE_DENY === ($ruleTypeOnePrivilege = $this->_getRuleType($resource, null, $privilege))) {
                            return false;
                        }
                    }
                    if (null !== ($ruleTypeAllPrivileges = $this->_getRuleType($resource, null, null))) {