ReadonlyidThe composition id (lib.properties.id of the published content)
ReadonlylibThe symbol classes by symbol name: what frame scripts reach as lib
ReadonlypropertiesThe values of the published lib.properties (its lists, such as the manifest, left out)
An instance of a symbol for the application to place, set up as the HTML template sets up the root it creates.
A loaded content, as the application uses it.