presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/thrift/ThriftHiveMetastore.java/ThriftHiveMetastore/listRoles
class ThriftHiveMetastore:    @Override
    public Set<String> listRoles()
    {
        try {
            return retry()
                    .stopOn(MetaException.class)
                    .stopOnIllegalExceptions()
                    .run("listRoles", stats.getListRoles().wrap(() -> {
                        try (ThriftMetastoreClient client = createMetastoreClient()) {
                            return ImmutableSet.copyOf(client.getRoleNames());
                        }
                    }));
        }
        catch (TException e) {
            throw new PrestoException(HIVE_METASTORE_ERROR, e);
        }
        catch (Exception e) {
            throw propagate(e);
        }
    }