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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 get_values(self, *args):
 """ Gets environment variables values. Usage:: {'HOME': u'/Users/JohnDoe'} {'HOME': u'/Users/JohnDoe', 'USER': u'JohnDoe'} :param \*args: Additional variables names to retrieve values from. :type \*args: \* :return: Variables : Values. :rtype: dict """


        args and self.__add_variables(*args)

        LOGGER.debug("> Object environment variables: '{0}'.".format(
            ",".join((key for key in self.__variables if key))))
        LOGGER.debug("> Available system environment variables: '{0}'".format(os.environ.keys()))

        for variable in self.__variables:
            value = os.environ.get(variable, None)
            self.__variables[variable] = foundations.strings.to_string(value) if value else None
        return self.__variables