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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 load_replace_candidate(self, filename=None, config=None):
 """ SCP file to device filesystem, defaults to candidate_config. Return None or raise exception """

        self.config_replace = True
        return_status, msg = self._load_candidate_wrapper(source_file=filename,
                                                          source_config=config,
                                                          dest_file=self.candidate_cfg,
                                                          file_system=self.dest_file_system)
        if not return_status:
            raise ReplaceConfigException(msg)