func TestBool(t *testing.T) {
	reset()

	ev := RegisterBoolVar(testVar, true, "")
	v, present := ev.Lookup()
	if !v {
		t.Errorf("Expected true, got %v", v)
	}
	if present {
		t.Errorf("Expected not present")
	}

	v = ev.Get()
	if !v {
		t.Errorf("Expected true, got %v", v)
	}

	_ = os.Setenv(testVar, "XXX")

	ev = RegisterBoolVar(testVar, true, "")
	v, present = ev.Lookup()
	if !v {