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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 fetchmany(self, size: int = None) -> Iterable[sqlite3.Row]: """Fetch up to `cursor.arraysize` number of rows."""

        args = ()  # type: Tuple[int, ...]
        if size is not None:
            args = (size,)
        return await self._execute(self._cursor.fetchmany, *args)