@BeforeClass
  public static void setUp() throws Exception {
    EnvFactory.getEnv().initClusterEnvironment();
    initCreateSQLStatement();
    insertData();
  }
Notice that, all test begins with "IoTDB" is integration test. All test which will start the
IoTDB server should be defined as integration test.

<p>This test stores NaN Values and retrieves them via SQL Interface.
integration-test/src/test/java/org/apache/iotdb/db/it/IoTDBInsertNaNIT.java