How best to encapsulate data retrieval and conversion stuff as shown in the `gustav.mixin.js` demo, so that it can be easily used in multiple components like `gustav.vue`?

The problem here is that from the component's perspective we're only interested in providing `ottoId` and receiving `gustav`. All other properties from data, computed, methods are at best irrelevant to the component - at worst may cause conflicts.

Is there any sane way I can stay in the "how a mixin would do it" kind of code, but achieve only the export of `computed.gustav`, `watch.ottoId` and `created`?