makeLoopbackNetwork = gateway => {
  return Far(
    'Loopback Network',
    /** @type {import('../types.js').EndoNetwork} */ ({
      addresses: () => [],
      supports: address => new URL(address).protocol === 'loop:',
      connect: address => {
        if (address !== 'loop:') {
          throw new Error(
            'Failed invariant: loopback only supports "loop:" address',
          );
        }
        return gateway;
      },
    }),
  );
}
@param {Promise<import('../types.js').EndoGateway>} gateway
@returns {import('@endo/far').FarRef<import('../types.js').EndoNetwork>}