docs: function () {
          var Compo = $component ({ $defaults:           { foo: 42 }})
          $assert ($untag (Compo.$definition.$defaults), { foo: 42 })
          $assert (        Compo.            $defaults,  { foo: 42 })
  
          var Compo2 = $component ({ $traits: [$trait ({ $defaults: { foo: 11 } })], $defaults: { } })
          $assert ($untag (Compo2.$definition.$defaults), { foo: 11 })
          $assert (        Compo2.            $defaults,  { foo: 11 })
      }