spark-submit job is not exiting until I hit ctrl+C if I use Check class

**Is your feature request related to a problem? Please describe.**

spark-submit job is not exiting until I hit ctrl+C if I use Check function

**Describe the solution you'd like**

Check function would start a self._spark_session.sparkContext._gateway server. If my code is completed, the server is still hang on that causes the spark job can't stop normally.

Adding a close function to class Check

def close(self):
self._spark_session.sparkContext._gateway.close()
return