Exploring adding setWatch/clearWatch (interrupt handling) to MCP23017 (MCP2308) Portexpander Ports

Great - you know you can also do stuff like:

(function() {
 var _setWatch = setWatch;
 setWatch = function(...) { _setWatch(...); }
})()

To fix up the existing setWatch implementation to how you want it. Any modules should then use your new setWatch.