public static String toJsonString(final Token<? extends TokenIdentifier> token
      ) throws IOException {
    return toJsonString(Token.class, toJsonMap(token));
  }
@Test
  public void testToJsonFromContentSummary() {
    String jsonString =
        "{\"ContentSummary\":{\"directoryCount\":33333,\"ecPolicy\":"
            + "\"RS-6-3-1024k\",\"fileCount\":22222,\"length\":11111,"
            + "\"quota\":44444,\"snapshotDirectoryCount\":1,"
            + "\"snapshotFileCount\":2,\"snapshotLength\":10,"
            + "\"snapshotSpaceConsumed\":30,\"spaceConsumed\":55555,"
            + "\"spaceQuota\":66666,\"typeQuota\":{}}}";

    long length = 11111;
    long fileCount = 22222;
    long directoryCount = 33333;
    long quota = 44444;
    long spaceConsumed = 55555;
    long spaceQuota = 66666;
    String ecPolicy = "RS-6-3-1024k";
    long snapshotLength = 10;
    long snapshotFileCount = 2;
    long snapshotDirectoryCount = 1;
    long snapshotSpaceConsumed = 30;

    ContentSummary contentSummary = new ContentSummary.Builder().length(length)
        .fileCount(fileCount).directoryCount(directoryCount).quota(quota)
        .spaceConsumed(spaceConsumed).spaceQuota(spaceQuota)
        .erasureCodingPolicy(ecPolicy).snapshotLength(snapshotLength)
        .snapshotFileCount(snapshotFileCount)
        .snapshotDirectoryCount(snapshotDirectoryCount)
        .snapshotSpaceConsumed(snapshotSpaceConsumed).build();

    Assert.assertEquals(jsonString, JsonUtil.toJsonString(contentSummary));
  }