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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, callback=_noop_callback):
 """Save this file. :param filename: the file to which to save the .sav file :type filename: str :param callback: a progress callback function :type callback: function """

        with open(filename, 'wb') as fp:
            self._save(fp, callback)