code: function (optionCollection, key, model, collection) {
          if (optionCollection) {
              return strTo(optionCollection, model, Collection) || collection;
          }
          return strTo(key, model, Collection) || null;
      }
docs: Similar to getSubModel except for collections and does not pass the parent collection if no option collection is specified and the schema key cannot locate a sub collection, then null is returned