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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 register_backend(self, config_contents):
 """Register a single API and its config contents. Args: config_contents: Dict containing API configuration. """

    if config_contents is None:
      return
    self.__register_class(config_contents)
    self.__api_configs.append(config_contents)
    self.__register_methods(config_contents)