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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 unpersist(self, blocking=False):
 """ Mark the RDD as non-persistent, and remove all blocks for it from memory and disk. .. versionchanged:: 3.0.0 Added optional argument `blocking` to specify whether to block until all blocks are deleted. """

        self.is_cached = False
        self._jrdd.unpersist(blocking)
        return self