function (obj) {
    if (obj.file && obj.file.data) {
      return obj.file.data instanceof EventEmitter;
    }
    return false;
  }
function (obj) {
    if (obj.file && obj.file.data) {
      return obj.file.data instanceof EventEmitter;
    }
    return false;
  }
function ( obj ) { if ( obj . file && obj . file . data ) { return obj . file . data instanceof EventEmitter ; } return false ; }
Determine if file data is a derivative of EventEmitter class.
https://nodejs.org/api/events.html#events_events
Determine if file data is a derivative of EventEmitter class . https : // nodejs . org / api / events . html#events_events