@Test
  public void testNullDefault() throws Throwable {
    final String SCRIPT_TEXT = "set hive.support.concurrency = false;\n" +
        "select null from " + tableName + " limit 1 ;\n";
    final String EXPECTED_PATTERN = "NULL";
    testScriptFile(SCRIPT_TEXT, getBaseArgs(miniHS2.getBaseJdbcURL()), EXPECTED_PATTERN, true);
  }
Select null from table , check how null is printed
Print PASSED or FAILED
itests/hive-unit/src/test/java/org/apache/hive/beeline/TestBeeLineWithArgs.java