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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 _init_metadata_service(self, version):
 """ Method to initialize the Metadata Service from the config data Args: version (string):
 Version of Boss API to use. Returns: None Raises: (KeyError):
 if given invalid version. """

        metadata_cfg = self._load_config_section(CONFIG_METADATA_SECTION)
        self._token_metadata = metadata_cfg[CONFIG_TOKEN]
        proto = metadata_cfg[CONFIG_PROTOCOL]
        host = metadata_cfg[CONFIG_HOST]

        self._metadata = MetadataService(host, version)
        self._metadata.base_protocol = proto
        self._metadata.set_auth(self._token_metadata)