apply..Root.applyInvoke the callable object f with elements of arr as arguments and p as its parent.
Parameters: any p, Callable f, Array arr
Return value: return value of calling f
NativeCallable, Callable
auto arr.=(Array());
arr.pushBack(1);
arr.pushBack(2);
apply(Root, log, arr);
Equivalent of Root.log(1, 2);.