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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 flatMap(self, f, preservesPartitioning=False):
 """ Return a new RDD by first applying a function to all elements of this RDD, and then flattening the results. [1, 1, 1, 2, 2, 3] [(2, 2), (2, 2), (3, 3), (3, 3), (4, 4), (4, 4)] """

        def func(s, iterator):
            return chain.from_iterable(map(fail_on_stopiteration(f), iterator))
        return self.mapPartitionsWithIndex(func, preservesPartitioning)