clear method
void
clear()
Removes all items from the vector.
Implementation
void clear() {
final hr = ptr.ref.vtable
.elementAt(15)
.cast<Pointer<NativeFunction<HRESULT Function(Pointer)>>>()
.value
.asFunction<int Function(Pointer)>()(ptr.ref.lpVtbl);
if (FAILED(hr)) throw WindowsException(hr);
}