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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 __add_symbols(self, cmd):
 """ Add all additional defined and undefined symbols. """


        if self.__config.define_symbols:
            symbols = self.__config.define_symbols
            cmd.append(''.join(
                [' -D"%s"' % def_symbol for def_symbol in symbols]))

        if self.__config.undefine_symbols:
            un_symbols = self.__config.undefine_symbols
            cmd.append(''.join(
                [' -U"%s"' % undef_symbol for undef_symbol in un_symbols]))

        return cmd