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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 next(self) -> Any: """Emits the next multipart body part."""

        # So, if we're at BOF, we need to skip till the boundary.
        if self._at_eof:
            return
        await self._maybe_release_last_part()
        if self._at_bof:
            await self._read_until_first_boundary()
            self._at_bof = False
        else:
            await self._read_boundary()
        if self._at_eof:  # we just read the last boundary, nothing to do there
            return
        self._last_part = await self.fetch_next_part()
        return self._last_part