presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/cache/CachingHiveMetastore.java/CachingHiveMetastore/createRole
class CachingHiveMetastore:    @Override
    public void createRole(String role, String grantor)
    {
        try {
            delegate.createRole(role, grantor);
        }
        finally {
            rolesCache.invalidateAll();
        }
    }