code: @Override
      public Citation convert(XBELCitation source) {
          if (source == null) {
              return null;
          }
  
          String name = source.getName();
  
          // Destination type
          Citation dest = CommonModelFactory.getInstance().createCitation(name);
  
          Calendar date = source.getDate();
          dest.setDate(date);
  
          String comment = source.getComment();
          dest.setComment(comment);
  
          String reference = source.getReference();
          dest.setReference(reference);
  
          CitationType type = source.getType();
          if (type != null) {
              dest.setType(fromString(type.value()));
          }
  
          if (source.isSetAuthorGroup()) {
              List<String> author = source.getAuthorGroup().getAuthor();
              dest.setAuthors(author);
          }
  
          return dest;
      }
docs: {@inheritDoc}