public function isAllowed($role, $resource) {

		if(false === is_string($role)) {
			return trigger_error(sprintf('Argument 1 passed to %s() must be of the type string, "%s" given', __METHOD__, gettype($role)), E_USER_ERROR);
		}

		if(false === is_string($resource)) {
			return trigger_error(sprintf('Argument 2 passed to %s() must be of the type string, "%s" given', __METHOD__, gettype($resource)), E_USER_ERROR);
		}

		if(true === isset($this -> permissions[$role][$resource])) {
			return $this -> permissions[$role][$resource];
		}

		return false;
	}