routes as root-routes and nested-routes

[J. Regner]

node.js version: 10.7.0

npm/yarn and version: npm 6.1.0

koa-router version: 7.4.0

koa version: 2.5.2

Code sample:

// --- Issues
const issueRouter = new Router({'prefix': '/issues'});

issueRouter.get('/', IssuesController.index);

// --- Projects
const projectRouter = new Router({'prefix': '/projects'});

projectRouter.get('/', ProjectsController.index);
projectRouter.get('/:id', ProjectsController.view);

projectRouter.use('/:id', issueRouter.routes());

// --- Router
const router = new Router();

router
    .use(projectRouter.routes())
    .use(issueRouter.routes());

export default router.routes();

Is it possible to get issueRouter routes as root-routes and nested-routes? Currently it seems not to be possible.
I want to use it as: /issues/PROJECT_ID+ISSUE_ID or over the project /projects/PROJECT_ID/issues/ISSUE_ID
Is this somehow possible if yes - how - if not maybe you can add support for this?