How to assign different border styles in Sketch?

I needed to assign different border styles for a shape, let's say rectangle. For example, I want to make a #666 1px top border and #333 2px bottom border like we do in CSS.

{
  border-top: 1px solid #666;
  border-bottom: 2px solid #333;
}

Anyone knows a practical way to do this? Any help would be appreciated.