t.Fatalf("response body incorrect: %v", string(body))
	}

	// Check that Unwrap works
	if trw.Unwrap() != rw {
		t.Fatalf("Unwrap returned wrong result: %v", trw.Unwrap())
	}
}

func TestHeadersAlreadyWritten(t *testing.T) {
	rw := httptest.NewRecorder()
	trw := &trackingResponseWriter{ResponseWriter: rw}

	if headersAlreadyWritten(trw) {
		t.Fatal("headers have not been written yet")
	}