BorderRadiusDirectional.horizontal constructor

const BorderRadiusDirectional.horizontal({Radius start: Radius.zero, Radius end: Radius.zero })

Creates a horizontally symmetrical border radius where the start and end sides of the rectangle have the same radii.

Implementation 

const BorderRadiusDirectional.horizontal({
  Radius start = Radius.zero,
  Radius end = Radius.zero,
}) : this.only(
  topStart: start,
  topEnd: end,
  bottomStart: start,
  bottomEnd: end,
);