public static NamenodeRole convert(NamenodeRoleProto role) {
    switch (role) {
    case NAMENODE:
      return NamenodeRole.NAMENODE;
    case BACKUP:
      return NamenodeRole.BACKUP;
    case CHECKPOINT:
      return NamenodeRole.CHECKPOINT;
    }
    return null;
  }
@Test
  public void testConvertExportedBlockKeys() {
    BlockKey[] keys = new BlockKey[] { getBlockKey(2), getBlockKey(3) };
    ExportedBlockKeys expKeys = new ExportedBlockKeys(true, 9, 10,
        getBlockKey(1), keys);
    ExportedBlockKeysProto expKeysProto = PBHelper.convert(expKeys);
    ExportedBlockKeys expKeys1 = PBHelper.convert(expKeysProto);
    compare(expKeys, expKeys1);
  }