--- Create a non-superuser role and check if it can access citus_internal schema functions
CREATE USER nonsuperuser CREATEROLE;
SET ROLE nonsuperuser;
--- The non-superuser role should not be able to access citus_internal functions
SELECT citus_internal.replace_isolation_tester_func();
ERROR:  permission denied for function replace_isolation_tester_func
RESET ROLE;
DROP USER nonsuperuser;