@Test
  public void testMROnTableWithTimestamp() throws Exception {
    util.createTable(tn, FAMILY);
    args.put(ImportTsv.COLUMNS_CONF_KEY, "HBASE_ROW_KEY,HBASE_TS_KEY,FAM:A,FAM:B");
    args.put(ImportTsv.SEPARATOR_CONF_KEY, ",");
    String data = "KEY,1234,VALUE1,VALUE2\n";

    doMROnTableTest(data, 1);
    util.deleteTable(tn);
  }
Force use of combiner in doMROnTableTest. Boolean. Default is true.
hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TestImportTsv.java