Example of unique constructor to enable model awareness

[draco2003]

Looks like there is currently only a mongoose adapter.

"Out of the box, model awareness works for any model that has a unique constructor."

Might help to show a small snippet of code of a unique constructor to solicit more adapters (or more existing modules to be compatible with this functionality).

Referencing: https://github.com/jaredhanson/www.locomotivejs.org/blob/master/content/guide/datastores.md