Doesn't do anything - is merely a type to represent an arbitrary shape in typespecs.
Summary
Types
@type t() :: Vivid.Arc.t() | Vivid.Bezier.t() | Vivid.Bitmap.t() | Vivid.Bounds.t() | Vivid.Box.t() | Vivid.Circle.t() | Vivid.Group.t() | Vivid.Line.t() | Vivid.Path.t() | Vivid.Point.t() | Vivid.Polygon.t() | Vivid.Region.t()