*/ interface ResourceInterface { /** * Checks if a timestamp represents the latest resource. * * @param integer $timestamp A UNIX timestamp * * @return Boolean True if the timestamp is up to date */ public function isFresh($timestamp); /** * Returns the content of the resource. * * @return string The content */ public function getContent(); /** * Returns a unique string for the current resource. * * @return string A unique string to identity the current resource */ public function __toString(); }