@AfterClass
  public static void tearDown() throws Exception {
    EnvFactory.getEnv().cleanClusterEnvironment();
  }
Notice that, all test begins with "IoTDB" is integration test. All test which will start the
IoTDB server should be defined as integration test.
integration-test/src/test/java/org/apache/iotdb/db/it/IoTDBFloatPrecisionIT.java