enum PaymentOptions { VISA, MASTERCARD, MADA, INSTALLMENT, APPLEPAY } extension PaymentOptions_ on PaymentOptions{ String value(){ switch(this){ case PaymentOptions.VISA: return "VISA"; break; case PaymentOptions.MASTERCARD: return "MASTERCARD"; break; case PaymentOptions.MADA: return "MADA"; break; case PaymentOptions.INSTALLMENT: return "INSTALLMENT"; break; case PaymentOptions.APPLEPAY: return "APPLEPAY"; break; } return null; } }