/**
   * make the hbase filter for selecting values of y-axis(response time) in order to select
   * transactions in scatter chart. 4 bytes for elapsed time should be attached for the prefix of
   * column qualifier for to use this filter.
   *
   * @param area
   * @param offsetTransactionId
   * @param offsetTransactionElapsed
   * @return
   */
  private Filter makeResponseTimeFilter(
      final SelectedScatterArea area,
      final TransactionId offsetTransactionId,
      int offsetTransactionElapsed) {
    // filter by response time
    ResponseTimeRange responseTimeRange = area.getResponseTimeRange();
    byte[] responseFrom = Bytes.toBytes(responseTimeRange.getFrom());
    byte[] responseTo = Bytes.toBytes(responseTimeRange.getTo());
    FilterList filterList = new FilterList(Operator.MUST_PASS_ALL);
    filterList.addFilter(
        new QualifierFilter(CompareOp.GREATER_OR_EQUAL, new BinaryPrefixComparator(responseFrom)));
    filterList.addFilter(
        new QualifierFilter(CompareOp.LESS_OR_EQUAL, new BinaryPrefixComparator(responseTo)));

    // add offset
    if (offsetTransactionId != null) {
      final Buffer buffer = new AutomaticBuffer(32);
      buffer.put(offsetTransactionElapsed);
      buffer.putPrefixedString(offsetTransactionId.getAgentId());
      buffer.putSVar(offsetTransactionId.getAgentStartTime());
      buffer.putVar(offsetTransactionId.getTransactionSequence());
      byte[] qualifierOffset = buffer.getBuffer();

      filterList.addFilter(
          new QualifierFilter(CompareOp.GREATER, new BinaryPrefixComparator(qualifierOffset)));
    }
    return filterList;
  }
 @Test
 public void diffSeqDesc() {
   TransactionId id1 = new TransactionId("A1", 1, 2);
   TransactionId id2 = new TransactionId("A1", 1, 1);
   Assert.assertEquals(1, id1.compareTo(id2));
 }
 @Test
 public void diffAgentStartTimeDesc() {
   TransactionId id1 = new TransactionId("A1", 2, 1);
   TransactionId id2 = new TransactionId("A1", 1, 1);
   Assert.assertEquals(1, id1.compareTo(id2));
 }
 @Test
 public void sameAll() {
   TransactionId id1 = new TransactionId("A1", 1, 1);
   TransactionId id2 = new TransactionId("A1", 1, 1);
   Assert.assertEquals(0, id1.compareTo(id2));
 }