addPeriods method
Implementation
void addPeriods(int periods) {
final hr = ptr.ref.vtable
.elementAt(67)
.cast<
Pointer<NativeFunction<HRESULT Function(Pointer, Int32 periods)>>>()
.value
.asFunction<
int Function(Pointer, int periods)>()(ptr.ref.lpVtbl, periods);
if (FAILED(hr)) throw WindowsException(hr);
}