easeInOutSine constant
A cubic animation curve that starts slowly, speeds up, and then ends slowly. This is similar to Curves.easeInOut, but with sinusoidal easing for a slightly less abrupt beginning and end.
Derived from Robert Penner’s easing functions.
Implementation
static const Cubic easeInOutSine = Cubic(0.445, 0.05, 0.55, 0.95);