if string(got) != appendResult {
		t.Fatalf("Append returns %q not %q", got, appendResult)
	}
	if &b[0] != &got[0] {
		t.Fatalf("Append allocated a new slice")
	}
}

func TestAppendln(t *testing.T) {
	b := make([]byte, 100)
	b = b[:copy(b, hello)]
	got := Appendln(b, "world,", 23)
	if string(got) != appendResult+"\n" {
		t.Fatalf("Appendln returns %q not %q", got, appendResult+"\n")
	}