function onRelease(hammer, callback) {
  callback.inputHandler = function (event) {
    if (event.isFinal) {
      callback(event);
    }
  };

  return hammer.on("hammer.input", callback.inputHandler);
}
Register a release event, taking place after a gesture
@param {Hammer} hammer       A hammer instance
@param {Function} callback   Callback, called as callback(event)
@returns {*}