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(_orderToken == null || _orderToken!.isEmpty) {
throw CFException(CFExceptionConstants.ORDER_TOKEN_NOT_PRESENT);
}
return CFSession(this);
}