Function warn

code/dependency-injection-module-system/public/app.js:3136–3139

(action, result)

  }

  function warn(action, result) {
    var warningCondition = false;
    warning(warningCondition, "This synthetic event is reused for performance reasons. If you're seeing this, " + "you're %s `%s` on a released/nullified synthetic event. %s. " + 'If you must keep the original synthetic event around, use event.persist(). ' + 'See https://fb.me/react-event-pooling for more information.', action, propName, result);
  }
}

function getPooledEvent(dispatchConfig, targetInst, nativeEvent, nativeInst) {