AddWeeks method
Implementation
void AddWeeks(int weeks) {
final hr = _thisPtr.ref.vtable
.elementAt(48)
.cast<Pointer<NativeFunction<HRESULT Function(Pointer, Int32 weeks)>>>()
.value
.asFunction<
int Function(Pointer, int weeks)>()(_thisPtr.ref.lpVtbl, weeks);
if (FAILED(hr)) throw WindowsException(hr);
}