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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 get_copy_from(self):
 """Returns a mapping of UID index -> AR object """

        # Create a mapping of source ARs for copy
        copy_from = self.request.form.get("copy_from", "").split(",")
        # clean out empty strings
        copy_from_uids = filter(lambda x: x, copy_from)
        out = dict().fromkeys(range(len(copy_from_uids)))
        for n, uid in enumerate(copy_from_uids):
            ar = self.get_object_by_uid(uid)
            if ar is None:
                continue
            out[n] = ar
        logger.info("get_copy_from: uids={}".format(copy_from_uids))
        return out