fromTween<T> method
Set animation explicitly by defining the Tween.
The callback exposes the currentValue value
Implementation
T? fromTween<T>(Tween<T?> Function(T? currentValue) fn, [String? name]) {
final curve = _curve;
final reserveCurve = _reserveCurve;
_curve = null;
_reserveCurve = null;
return _fromTween(fn, curve, reserveCurve, name ?? '');
}