code: @Override
  	public LinkedHashMap<String, ArrayList<DBReferenceInfo>> getDatabaseReferences()  {
  		LinkedHashMap<String, ArrayList<DBReferenceInfo>> databaseReferencesHashMap = new LinkedHashMap<String, ArrayList<DBReferenceInfo>>();
  		if (uniprotDoc == null) {
  			return databaseReferencesHashMap;
  		}
  
  		try {
  			Element uniprotElement = uniprotDoc.getDocumentElement();
  			Element entryElement = XMLHelper.selectSingleElement(uniprotElement, "entry");
  			ArrayList<Element> dbreferenceElementList = XMLHelper.selectElements(entryElement, "dbReference");
  			for (Element element : dbreferenceElementList) {
  				String type = element.getAttribute("type");
  				String id = element.getAttribute("id");
  				ArrayList<DBReferenceInfo> idlist = databaseReferencesHashMap.get(type);
  				if (idlist == null) {
  					idlist = new ArrayList<DBReferenceInfo>();
  					databaseReferencesHashMap.put(type, idlist);
  				}
  				DBReferenceInfo dbreferenceInfo = new DBReferenceInfo(type, id);
  				ArrayList<Element> propertyElementList = XMLHelper.selectElements(element, "property");
  				for (Element propertyElement : propertyElementList) {
  					String propertyType = propertyElement.getAttribute("type");
  					String propertyValue = propertyElement.getAttribute("value");
  					dbreferenceInfo.addProperty(propertyType, propertyValue);
  				}
  
  				idlist.add(dbreferenceInfo);
  			}
  		} catch (XPathExpressionException e) {
  			logger.error("Problems while parsing db references in UniProt XML: {}. No db references will be available.",e.getMessage());
  			return new LinkedHashMap<String, ArrayList<DBReferenceInfo>>();
  		}
  
  		return databaseReferencesHashMap;
  	}
docs: The Uniprot mappings to other database identifiers for this sequence
  @return