Setting baseclass on TypeScript clients

I would like to provide the generated clients with a baseclass so they can call this.getBaseUrl() as the url they need to call is only known at deployment time. I will use aurelia-configuration to provide the url at that time. I can make the base client but the code does not compile since a

import { ClientBase } from './client-base';

is missing from the head of the generated file. I am using msbuild like this <Exec Command="$(NSwagExe) swagger2tsclient /input:swagger.json /output:src/server/backendservice.ts /UseGetBaseUrlMethod:true /ClientBaseClass:ClientBase" />

Am I doing this wrong? If this is currently not supported, would it make sense for the generator to infer the filename from the base class name?

[ddlaat]

settings.TypeScriptGeneratorSettings.ExtensionCode = "import {BaseClient} from "./baseClient";";

[ddlaat]

Thank you for the fast response. I see it now. TypeScriptGeneratorSettings is also a property of TypeScriptClientGeneratorSettings.