How to know if timeout occurred in cypher query?

I'm using apoc.cypher.runTimeboxed Timeboxed Cypher statements - APOC Extended Documentation

I'm using the HTTP API of neo4j. I'm making HTTP post requests like below.

HTTP request on developer tools of my browser

Here I do NOT see any difference if the results are really empty or if the results are empty because TIMEOUT OCCURRED. I think there should be a warning or error message.