easeInBack constant Null safety
A cubic animation curve that starts slowly and ends quickly. This curve is similar to Curves.elasticIn in that it overshoots its bounds before reaching its end. Instead of repeated swinging motions before ascending, though, this curve overshoots once, then continues to ascend.
Derived from Robert Penner’s easing functions.
static const Cubic easeInBack = Cubic(0.6, -0.28, 0.735, 0.045);