I came across this function code in a javascript library and not really sure how the return works.
function(t, e, r) {
return 2 === arguments.length && "function" == typeof e && (r = e,e =null) , Cn(t, e, n, r)
}
if(2 === arguments.length && "function" == typeof e)
(r = e,e = null) , return Cn(t, e, n, r)