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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 add_local_charm_dir(self, charm_dir, series):
 """Upload a local charm to the model. This will automatically generate an archive from the charm dir. :param charm_dir: Path to the charm directory :param series: Charm series """

        fh = tempfile.NamedTemporaryFile()
        CharmArchiveGenerator(charm_dir).make_archive(fh.name)
        with fh:
            func = partial(
                self.add_local_charm, fh, series, os.stat(fh.name).st_size)
            charm_url = await self._connector.loop.run_in_executor(None, func)

        log.debug('Uploaded local charm: %s -> %s', charm_dir, charm_url)
        return charm_url