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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 format(self, format_target, remove_obsolete=True):
 """ Changes the internal self.format_string_object format target based on input. Also checks to see if input is an entry in the config file in case we want to switch to a preexisting config format. :param format_target: str, input for the new format type. All strings will be the new tokens. :param remove_obsolete: bool, dictates whether we are removing the obselete tokens or not that previously existed :return: None """

        original_format, original_format_order = (self.format, self.format_order)

        try:
            format_target = self.CFG.get(format_target, return_type=str, throw_null_return_error=True)
        except (errors.ResourceNotFoundError, KeyError):
            pass

        self.format_string_object.swap_format(format_target)
        self._update_tokens_from_swap_format(original_format, original_format_order, remove_obsolete=remove_obsolete)