message: Derive ImodelGatewayImpl from Gateway (now its API can be checked for missing/incorrect signatures against the IModelGateway definition in the registerImplementation call).
diff: @@ -16,7 +16,7 @@ import { IModelGateway } from "../gateway/IModelGateway";
  /** The backend implementation of IModelGateway.
  * @hidden
  */
  -export class IModelGatewayImpl extends IModelGateway {
  +export class IModelGatewayImpl extends Gateway {
  public static register() {
  Gateway.registerImplementation(IModelGateway, IModelGatewayImpl);
  }
  