code: function makeModulesGetHostnameProto(module, version, instance) {
    var getHostnameRequest = new apphosting.GetHostnameRequest();
    getHostnameRequest.setModule(module);
    getHostnameRequest.setVersion(version);
    getHostnameRequest.setInstance(instance);
    return getHostnameRequest;
  }
docs: Return a modules get hostname proto.
  
  @param {!string} module module name
  @param {!string} version module version
  @param {!string} instance module instance
  @return {apphosting.GetHostnameRequest} a modules get hostname proto