Function warn

third_party/subscriptions-project/swg.js:2953–2955

* @param {...*} var_args [description]

(var_args)

 * @param  {...*} var_args [description]
 */
function warn(var_args) {
  console.warn.apply(console, arguments);
}

/**
 * Throws an error if the first argument isn't trueish.