build method
Implementation
CFSession build() {
if (_environment == null) {
throw CFException(CFExceptionConstants.ENVIRONMENT_NOT_PRESENT);
}
if (_orderId == null || _orderId!.isEmpty) {
throw CFException(CFExceptionConstants.ORDER_ID_NOT_PRESENT);
}
if(_paymentSessionId == null || _paymentSessionId!.isEmpty) {
throw CFException(CFExceptionConstants.PAYMENT_SESSION_ID_NOT_PRESENT);
}
return CFSession(this);
}