window property Null safety
final
        Implementation
static final NormalArgOperation window = NormalArgOperation(
    arg: DigitArg(
        max: 7,
        calc: (m, i) {
          if (!m.isFloatMode) {
            m.display.window = i * 8;
          }
        }),
    stackLift: StackLift.neutral,
    name: 'WINDOW');