code: /** 
   * Test add block
   * @throws Exception
   */
  @Test public void AddBlockTest() throws Exception {
    mTfs.createFile("/xyz",64);
    TachyonFile file=mTfs.getFile("/xyz");
    OutputStream os=file.getOutStream(WriteType.MUST_CACHE);
    for (int k=0; k < 1000; k++) {
      os.write(k);
    }
    os.close();
    ClientFileInfo fInfo=mLocalTachyonCluster.getMasterInfo().getClientFileInfo("/xyz");
    mLocalTachyonCluster.stop();
    AddBlockTestUtil(fInfo);
    String editLogPath=mLocalTachyonCluster.getEditLogPath();
    UnderFileSystem.get(editLogPath).delete(editLogPath,true);
    AddBlockTestUtil(fInfo);
  }
  