@Override
  @InterfaceAudience.Private
  public void readFields(DataInput in) throws IOException {
    this.length = in.readLong();
    this.fileCount = in.readLong();
    this.directoryCount = in.readLong();
    setQuota(in.readLong());
    setSpaceConsumed(in.readLong());
    setSpaceQuota(in.readLong());
  }
@Test
  public void testReadFields() throws IOException {
    long length = 11111;
    long fileCount = 22222;
    long directoryCount = 33333;
    long quota = 44444;
    long spaceConsumed = 55555;
    long spaceQuota = 66666;

    ContentSummary contentSummary = new ContentSummary.Builder().build();

    DataInput in = mock(DataInput.class);
    when(in.readLong()).thenReturn(length).thenReturn(fileCount)
        .thenReturn(directoryCount).thenReturn(quota).thenReturn(spaceConsumed)
        .thenReturn(spaceQuota);

    contentSummary.readFields(in);
    assertEquals("getLength", length, contentSummary.getLength());
    assertEquals("getFileCount", fileCount, contentSummary.getFileCount());
    assertEquals("getDirectoryCount", directoryCount,
        contentSummary.getDirectoryCount());
    assertEquals("getQuota", quota, contentSummary.getQuota());
    assertEquals("getSpaceConsumed", spaceConsumed,
        contentSummary.getSpaceConsumed());
    assertEquals("getSpaceQuota", spaceQuota, contentSummary.getSpaceQuota());
  }