node_modules/rambda/src/chain.js - devtools/devtools-frontend - Git at Google

 export function chain(fn, list){
   if (arguments.length === 1){
     return _list => chain(fn, _list)
   }

   return [].concat(...list.map(fn))
 }
	export function chain(fn, list){
	if (arguments.length === 1){
	return _list => chain(fn, _list)
	}

	return [].concat(...list.map(fn))
	}