How to use the @algolia/client-common.addMethods function in @algolia/client-common

const transporter = createTransporter({
    ...options,
    // No retry strategy on recommendation client
    hostsCache: createNullCache(),
  });

  const appId = options.appId;

  transporter.setHosts([{ url: `recommendation.${region}.algolia.com`, accept: CallEnum.Any }]);
  transporter.addHeaders({
    ...auth.headers(),
    ...{ 'content-type': 'application/json' },
  });
  transporter.addQueryParameters(auth.queryParameters());

  return addMethods({ appId, transporter }, options.methods);
};

const transporter = createTransporter({
    ...options,
    // No retry strategy on recommendation client
    hostsCache: createNullCache(),
  });

  const appId = options.appId;

  transporter.setHosts([{ url: `analytics.${region}.algolia.com`, accept: CallEnum.Any }]);
  transporter.addHeaders({
    ...auth.headers(),
    ...{ 'content-type': 'application/json' },
  });
  transporter.addQueryParameters(auth.queryParameters());

  return addMethods({ appId, transporter }, options.methods);
};

transporter.addHeaders({
    ...auth.headers(),
    ...{ 'content-type': 'application/x-www-form-urlencoded' },
  });

  transporter.addQueryParameters(auth.queryParameters());

  const base = {
    transporter,
    appId,
    addAlgoliaAgent(segment: string, version?: string): void {
      transporter.userAgent.add({ segment, version });
    },
  };

  return addMethods(base, options.methods);
};

return (indexName, options = {}) => {
    const searchIndex: SearchIndex = {
      transporter: base.transporter,
      appId: base.appId,
      indexName,
    };

    return addMethods(searchIndex, options.methods);
  };
};