code: @SuppressWarnings("unchecked")
      public final FindableDocument<? extends GedObject, ? extends GedDocument<?>>
          get(final Class<? extends GedObject> clazz) {
          return (FindableDocument<? extends GedObject, ? extends GedDocument<?>>)
                  classToRepoMap .get(clazz);
      }
docs: Get a repository based on the class of ged object we are working with.
  
  @param clazz the class of ged object
  @return the repository