Angular routing: How to access parent route param in child canLoad

Question

Here's what I have for routes:

  {
    path: ':class_id',
    component: Class_Root_Component,
    children: [
      {
        path: 'members',
        canLoad: [ Class_Members_Can_Load ],
        loadChildren: () => import('../../class-members/class-members.module')
          .then((m) => m.Class_Members_Module)
      }
    ],
  },

I need to access the :class_id param in the canLoad guard to run a check.

How do I access :class_id within the child route canLoad guard?

The canLoad function params route: Route and segments: UrlSegment[] do not contain it as a param.