Set a Java system property, such as spark.executor.memory. This must
        must be invoked before instantiating SparkContext.

def setSystemProperty(cls, key, value):
        """
        Set a Java system property, such as spark.executor.memory. This must
        must be invoked before instantiating SparkContext.
        """
        SparkContext._ensure_initialized()
        SparkContext._jvm.java.lang.System.setProperty(key, value)