Appends a stroked border rectangle inside the given @outline.
The four sides of the border can have different widths and colors.
a GskRoundedRect describing the outline of the border
the stroke width of the border on the top, right, bottom and left side respectively.
the color used on the top, right, bottom and left side.
See Implementation
Appends a stroked border rectangle inside the given @outline.
The four sides of the border can have different widths and colors.