code: private TransactionSupportEnum getTransactionSupport(Connector connector, Activation activation)
     {
        if (activation.getTransactionSupport() != null)
           return activation.getTransactionSupport();
  
        if (connector.getResourceadapter().getOutboundResourceadapter() != null)
           return connector.getResourceadapter().getOutboundResourceadapter().getTransactionSupport();
  
        // We have to assume XA for pure inbound, overrides is done with activation
        return TransactionSupportEnum.XATransaction;
     }
docs: Get the transaction support level
  @param connector The spec metadata
  @param activation The activation
  @return True if XA, otherwise false