decrement method

void decrement({
  1. num decrement = 1,
})

If Data is of type int, double, float or any num, you can decrement (default 1)

Implementation

void decrement({num decrement = 1}) {
  this.data = ((this.data as num) - decrement) as T?;
  if (isDisposed) return;
  notifyListeners();
}