JpsElementCollectionRole<JpsLibraryRoot> (JpsOrderRootType type) { JpsElementCollectionRole<JpsLibraryRoot> role = ourRootRoles.get(type); if (role != null) return role; ourRootRoles.putIfAbsent(type, JpsElementCollectionRole.create(new JpsLibraryRootRole(type))); return ourRootRoles.get(type); }