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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 package_releases(self, package, url_fmt=lambda u: u):
 """List all versions of a package Along with the version, the caller also receives the file list with all the available formats. """

        return [{
            'name': package,
            'version': version,
            'urls': [self.get_urlhash(f, url_fmt) for f in files]
        } for version, files in self.storage.get(package, {}).items()]