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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 get_url(self, version=None):
 """ Return the filename of the bundled bundle """

        if self.fixed_bundle_url:
            return self.fixed_bundle_url
        return '%s.%s.%s' % (os.path.join(self.bundle_url_root, self.bundle_filename), version or self.get_version(), self.bundle_type)