in core/nodejsActionBase/runner.js [204:211]
function splitMainHandler(handler) {
let matches = handler.match(/^([^.]+)$|^([^.]+)\.(.+)$/);
if (matches && matches.length == 4) {
let index = matches[2];
let main = matches[3] || matches[1];
return [index, main]
} else return undefined
}