func checkBinDir(t *testing.T, tempCNIBinDir, op string, files ...string) error {
	t.Helper()
	for _, f := range files {
		if _, err := os.Stat(tempCNIBinDir + "/" + f); !os.IsNotExist(err) {
			if op == "add" {
				t.Logf("PASS: File %v was added to %v", f, tempCNIBinDir)
				return nil
			} else if op == "del" {
				return fmt.Errorf("FAIL: File %v was not removed from %v", f, tempCNIBinDir)