protected final Promise<Void> call(final ResponsePromise responsePromise) { final ResponseTransformation<Object> responseTransformation = DefaultResponseTransformation.builder() .ok(constant((Void) null)) .created(constant((Void) null)) .noContent(constant((Void) null)) .others(AbstractAsynchronousRestClient.errorFunction()) .build(); return new DelegatingPromise(responsePromise.transform(responseTransformation)); }