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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 _do_save_as(self, filename):
 """Closes connection, copies DB file, and opens again pointing to new file **Note** if filename equals current filename, does nothing! """

        if filename != self.filename:
            self._ensure_filename()
            self._close_if_open()
            shutil.copyfile(self.filename, filename)
            self.__get_conn(filename=filename)