void addControl(NgControl dir)

Add a control to this form.

Source 

void addControl(NgControl dir) {
  var container = _findContainer(dir.path);
  var ctrl = new Control();
  container.addControl(dir.name, ctrl);
  scheduleMicrotask(() {
    setUpControl(ctrl, dir);
    ctrl.updateValueAndValidity(emitEvent: false);
  });
}