package integers import ( "fmt" "testing" ) func TestAdder(t *testing.T) { sum := Add(2, 2) // Output: 9 expected := 4 if sum != expected { t.Errorf("expected '%d' but got '%d'", expected, sum) } } // Runnable example testing func ExampleAdd() { fmt.Println(Add(2, 4)) // Output: 6 }