animated method
Implementation
StyleContext animated({
final Duration delay = Duration.zero,
final Duration duration = const Duration(milliseconds: 500),
final Curve curve = Curves.easeInOut,
}) {
_assertUseOnce(_duration == Duration.zero, "animated()");
final (d, c) = _delayedCurve(delay, duration, curve);
_duration = d;
_curve = c;
return this;
}