presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/file/FileHiveMetastore.java/FileHiveMetastore/toString
class FileHiveMetastore:        @Override
        public String toString()
        {
            return toStringHelper(this)
                    .add("role", role)
                    .add("grantee", grantee)
                    .toString();
        }