code: protected void marshallAttributes(XMLObject samlObject, Element domElement) throws MarshallingException {
  
      MetadataServiceList mdsl = (MetadataServiceList) samlObject;
  
      if (mdsl.getID() != null) {
        domElement.setAttributeNS(null, MetadataServiceList.ID_ATTR_NAME, mdsl.getID());
        domElement.setIdAttributeNS(null, MetadataServiceList.ID_ATTR_NAME, true);
      }
      if (mdsl.getVersion() != null) {
        domElement.setAttributeNS(null, MetadataServiceList.VERSION_ATTR_NAME, mdsl.getVersion().toString());
      }
      if (mdsl.getIssueDate() != null) {
        domElement.setAttributeNS(null, MetadataServiceList.ISSUE_DATE_ATTR_NAME,
          SAMLConfigurationSupport.getSAMLDateFormatter().print(mdsl.getIssueDate()));
      }
      if (mdsl.getNextUpdate() != null) {
        domElement.setAttributeNS(null, MetadataServiceList.NEXT_UPDATE_ATTR_NAME,
          SAMLConfigurationSupport.getSAMLDateFormatter().print(mdsl.getNextUpdate()));
      }
    }
docs: {@inheritDoc}