Blueprint extends pathing

Hi, I'm writing a blueprint that should extend another custom theme blueprint I've made. The base blueprint is located at [theme name]/blueprints/single/linkable.yaml

Given this path, how can I extend this blueprint? If I write:

'@extends': type: linkable
context: blueprints://single

It doesn't find the blueprint.

Try this:

'@extends': single/linkable

Context should already be blueprints, so you shouldn't need it.

The way I've been able to solve this myself:

'@extends':
  type: linkable
  context: theme://blueprints/single

However, rhuksters' approach also works.