function isPresto() {
  var opera = window.opera;
  return (
    typeof opera === 'object' &&
    typeof opera.version === 'function' &&
    parseInt(opera.version(), 10) <= 12
  );
}
@param {string} topLevelType Record from `EventConstants`.
@param {DOMEventTarget} topLevelTarget The listening component root node.
@param {string} topLevelTargetID ID of `topLevelTarget`.
@param {object} nativeEvent Native browser event.
@return {*} An accumulation of synthetic events.
@see {EventPluginHub.extractEvents}