code: public Layout layoutFor(Class<? extends Storable> type, int generation)
          throws FetchException, FetchNoneException
      {
          StoredLayout storedLayout =
              mLayoutStorage.query("storableTypeName = ? & generation = ?")
              .with(type.getName()).with(generation)
              .loadOne();
          return new Layout(this, storedLayout);
      }
docs: Returns the layout for a particular generation of the given type.
  
  @param generation desired generation
  @throws FetchNoneException if generation not found