public function toXMLString()
 {
     $str = '';
     $str .= parent::toXMLString();
     if ($this->SetCustomerBillingAgreementRequestDetails != null) {
         $str .= '<ebl:SetCustomerBillingAgreementRequestDetails>';
         $str .= $this->SetCustomerBillingAgreementRequestDetails->toXMLString();
         $str .= '</ebl:SetCustomerBillingAgreementRequestDetails>';
     }
     return $str;
 }
 public function toXMLString()
 {
     $str = '';
     $str .= parent::toXMLString();
     if ($this->SetCustomerBillingAgreementRequestDetails != null) {
         //prop is not a collection
         //prop is complex
         //prop is not enum
         //does not contain attribute or is attribute
         $str .= '<ebl:SetCustomerBillingAgreementRequestDetails>';
         $str .= $this->SetCustomerBillingAgreementRequestDetails->toXMLString();
         $str .= '</ebl:SetCustomerBillingAgreementRequestDetails>';
     }
     return $str;
 }