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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def conf(self):
 """Runtime configuration interface for Spark. This is the interface through which the user can get and set all Spark and Hadoop configurations that are relevant to Spark SQL. When getting the value of a config, this defaults to the value set in the underlying :class:`SparkContext`, if any. """

        if not hasattr(self, "_conf"):
            self._conf = RuntimeConfig(self._jsparkSession.conf())
        return self._conf