/**
  * Get, or create if there is none, a migration annotation for a group.
  *
  * @param source the source of the annotation
  * @param representation the DRepresentation
  * @param eObject the data of the annotation
  * @return the annotation entry
  */
 public static AnnotationEntry getOrCreateAnnotation(
     final String source, final DRepresentation representation, final EObject eObject) {
   AnnotationEntry annotation =
       new DRepresentationQuery(representation).getAnnotation(source, eObject).get();
   if (annotation == null && eObject != null) {
     annotation = DescriptionFactory.eINSTANCE.createAnnotationEntry();
     annotation.setSource(source);
     annotation.setData(eObject);
     representation.getOwnedAnnotationEntries().add(annotation);
   }
   return annotation;
 }