on_child_added 문의

아래와 같이 콘솔에서 메시지가 뜨는데 어떻게 처리를 하면 될까요??

Uncaught ReferenceError: summary is not defined

at on_child_added ((index):112)

at EventRegistration.js:169

at Object.t.exceptionGuard (util.js:536)

at e.raise (EventQueue.js:158)

at e.li (EventQueue.js:111)

at e.raiseEventsForChangedPath (EventQueue.js:95)

at e.setWithPriority (Repo.js:283)

at t.set (Reference.js:108)

at t.push (Reference.js:240)

at save_data ((index):122)