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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 print_help(self, file=None):
 """ recursively call all command parsers' helps """

        output = file or self.stderr
        CustomStderrOptionParser.print_help(self, output)
        output.write("\nCommands:\n")
        for command_def in self.command_definitions.values():
            command_def.opt_parser.print_help(output)
            output.write("\n")