@NotNull
  OrderRootsCache getCache() {
    LOG.assertTrue(myCache != null, "Caching is not supported for ModifiableRootModel");
    LOG.assertTrue(myCondition == null, "Caching not supported for OrderEnumerator with 'satisfying(Condition)' option");
    LOG.assertTrue(myModulesProvider == null, "Caching not supported for OrderEnumerator with 'using(ModulesProvider)' option");
    return myCache;
  }
@NotNull
  OrderRootsCache getCache()