def register_backend(self, config_contents):
if config_contents is None:<EOL><INDENT>return<EOL><DEDENT>self.__register_class(config_contents)<EOL>self.__api_configs.append(config_contents)<EOL>self.__register_methods(config_contents)<EOL>
Register a single API and its config contents.

        Args:
          config_contents: Dict containing API configuration.