code: @Override
    public List<String> getReconfigurableProperties() {
      // only allow reconfiguration of namesystem's reconfigurable properties
      List<String> properties = namesystem.getReconfigurableProperties();
      properties.add("fs.trash.interval");
      properties.add("dfs.enableHftp");
      properties.add(FSConstants.DFS_NAMENODE_RPC_ADDRESS_KEY + "0");
      properties.add(FSConstants.DFS_NAMENODE_RPC_ADDRESS_KEY + "1");
      return properties;
    }
docs: {@inheritDoc}