Scalr\Acl\Role\RoleObject::isAllowed PHP Method

    public function isAllowed($resourceId, $permissionId = null)
    {
        $allowed = null;
        $resourceDefinition = Resource\Definition::get($resourceId);
        if ($resourceDefinition === null) {
            throw new Exception\RoleObjectException(sprintf("%s ACL resource (0x%x).", in_array($resourceId, Acl::getDisabledResources()) ? 'Disabled' : 'Unknown', intval($resourceId)));
        }
        if (!empty($permissionId) && !$resourceDefinition->hasPermission($permissionId)) {
            if (!($resourceId == Acl::RESOURCE_OWN_FARMS && $permissionId == Acl::PERM_FARMS_CHANGE_OWNERSHIP)) {
                throw new Exception\RoleObjectException(sprintf("Unknown permission (%s) for resource '%s' (0x%x).", $permissionId, $resourceDefinition->getName(), intval($resourceId)));
            }
        }
        //Checks if resource is defined for the role
        $resource = $this->getResource($resourceId);
        if ($permissionId !== null && $resource !== null) {
            //If resource is defined we can check unique permission.
            //Checks if permission is defined
            $permission = $resource->getPermission($permissionId);
            //Checks access to unuque permission of the specified resource for the role.
            //If resource isn't allowed it automatically forbids all related permissions.
            $allowed = $permission !== null && $resource->isGranted() !== null ? $resource->isGranted() && $permission->isGranted() : null;
        } else {
            //Checks access to the resource for the role
            $allowed = $resource !== null ? $resource->isGranted() : null;
        }
        return $allowed;
    }

 /**
  * {@inheritdoc}
  * @see Scalr\Acl\Role.RoleObject::isOverridden()
  */
 public function isOverridden($resourceId, $permissionId = null)
 {
     $overridden = parent::isAllowed($resourceId, $permissionId) !== null;
     return $overridden;
 }