java-testinglisted

# Testing code that uses an APIMatic Java SDK The SDK ships **no mocking helpers for consumers**. Its transport is OkHttp (`io.apimatic:okhttp-client-adapter`), and the injection point is `httpClientConfig(b -> b.httpClientInstance(okHttpClient))`. Supplying an `OkHttpClient` whose interceptor returns canned responses is the in-process seam: no network, no global patching, and no dependence on the SDK's internals. > There is **no base-URL override**. The URL comes from the `Environment`/`Server` enums, so pointing the > client at a local mock server is not a matter of setting a property — either intercept inside OkHttp > (below) or, if you really want a live socket, run a mock server and rewrite the request URL in an > interceptor. The samples below use JUnit 5 for reference only — mirror whatever the project already uses. ## What you can substitute, and what you cannot **This SDK ships no interfaces, so there is nothing for a mocking library to substitute.** The client is `public final` with a private constructor, and every controller is a `public final` class with no interface behind it — most mocking libraries cannot subclass either without extra configuration. So put a narrow interface of your own in front of the SDK, implement it over the client — calling `client.get{Controller}().{operation}(...)` and returning whatever your callers need — and test *that* against the stub interceptor below. See **java-client-initialization**. ## A reusable stub helper ```java imp