presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/cache/CachingHiveMetastore.java/CachingHiveMetastore/toString
class CachingHiveMetastore:        @Override
        public String toString()
        {
            return toStringHelper(this)
                    .add("identity", identity)
                    .add("key", key)
                    .toString();
        }