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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:
 async def rollback_prepared(self, xid, *, is_prepared=True):
 """Rollback prepared twophase transaction."""

        if not is_prepared:
            await self.execute("XA END '%s'" % xid)
        await self.execute("XA ROLLBACK '%s'" % xid)