code: private ResourceReference parseDocumentLink(StringBuilder content)
      {
          // Extract any query string.
          String queryString = null;
          String text = parseElementAfterString(content, SEPARATOR_QUERYSTRING);
          if (text != null) {
              queryString = removeEscapesFromExtraParts(text);
          }
  
          // Extract any anchor.
          String anchor = null;
          text = parseElementAfterString(content, SEPARATOR_ANCHOR);
          if (text != null) {
              anchor = removeEscapesFromExtraParts(text);
          }
  
          // Make sure to unescape the remaining reference string.
          String unescapedReferenceString = removeEscapesFromReferencePart(content.toString());
          // Parse the string as an untyped link reference.
          ResourceReference reference = untypedLinkReferenceParser.parse(unescapedReferenceString);
          reference.setTyped(false);
  
          // Set any previously extracted parameters.
          if (StringUtils.isNotBlank(queryString)) {
              reference.setParameter(DocumentResourceReference.QUERY_STRING, queryString);
          }
          if (StringUtils.isNotBlank(anchor)) {
              reference.setParameter(DocumentResourceReference.ANCHOR, anchor);
          }
  
          return reference;
      }
docs: Construct a Document Link reference out of the passed content.
  
  @param content the string containing the Document link reference
  @return the parsed Link Object corresponding to the Document link reference