shortcut to assign instance as a global variable

[line-o]

Instead of having to write below code to be able to reference the instance with id test as $test

<fx-model>
  <fx-instance id="test"><data>something</data></fx-instance>
  <fx-vars name="test" value="instance('test')"></fx-vars>
</fx-model>

I propose to add the as attribute to create that ... link(?)

<fx-model>
  <fx-instance id="test" as="test"><data>something</data></fx-instance>
</fx-model>