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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 save(self, filename, format=None, **kwargs):
 """ Save the object to file given by filename. """

        if format is None:
            # try to derive protocol from file extension
            format = format_from_extension(filename)
        with file(filename, 'wb') as fp:
            self.save_to_file_object(fp, format, **kwargs)