Where can I find function prototype needed for each events

I want to implement job events but I could not find our function prototype needed to pass at callback parameters

https://github.com/Automattic/kue/blob/master/Readme.md#job-events

here in sample only few events are covert but what about other events ? how can i know about callback function's prototype.

Start with Readme.md#job-events and compare the documented event examples with the other job events exposed by Kue. Trace the event callback definitions in the repository to identify each callback prototype, then update the README so users can find the signatures for all events; done means the event documentation is complete and unambiguous.

Written by the indexing model from the issue text.