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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 _regroup_mergedRDD(self):
 """A common pattern is we want to call groupby again on the dataframes so we can use the groupby functions. """

        myargs = self._myargs
        mykwargs = self._mykwargs
        self._prep_pandas_groupby()

        def regroup(df):
            return df.groupby(*myargs, **mykwargs)

        return self._mergedRDD.mapValues(regroup)