presto-hive/src/main/java/io/prestosql/plugin/hive/HiveMetadata.java/HiveMetadata/listRoleGrants
class HiveMetadata:    @Override
    public Set<RoleGrant> listRoleGrants(ConnectorSession session, PrestoPrincipal principal)
    {
        return ImmutableSet.copyOf(accessControlMetadata.listRoleGrants(session, HivePrincipal.from(principal)));
    }