You can now add the following to pubspec.yaml:

    
...
flutter:
  ...
  deferred-components:
    - name: boxComponent
      libraries:
        - package:MyAppName/box.Dart
  ...
    
    To assign a loading unit to a deferred component,
add any Dart lib in the loading unit into the
libraries section of the feature module.
Keep the following guidelines in mind:

    

        Loading units should not be included
    in more than one component.
      

        Including one Dart library from a
    loading unit indicates that the entire loading
    unit is assigned to the deferred component.
      

        All loading units not assigned to
    a deferred component are included in the base component,
    which always exists implicitly.
      

        Loading units assigned to the same
    deferred component are downloaded, installed,
    and shipped together.