It seems the link to BasePolicy is broken in the following page: https://docs.adonisjs.com/guides/security/authorization#defining-policies
It currently points to: https://github.com/adonisjs/bouncer/blob/main/src/base_policy.ts which is broken.
I am available to put together a PR to fix the documentation if given the correct link.
Here is the exact location of the broken link: https://github.com/adonisjs/v6-docs/blob/main/content/docs/security/authorization.md?plain=1#L227
