code: @Override
      public XBELAnnotationGroup convert(AnnotationGroup source) {
          if (source == null) return null;
  
          List<Annotation> annotations = source.getAnnotations();
          Citation citation = source.getCitation();
          Evidence evidence = source.getEvidence();
  
          XBELAnnotationGroup xag = new XBELAnnotationGroup();
          List<Object> list = xag.getAnnotationOrEvidenceOrCitation();
  
          if (hasItems(annotations)) {
              // Defer to AnnotationConverter
              AnnotationConverter aConverter = new AnnotationConverter();
              for (final Annotation a : annotations) {
                  XBELAnnotation xa = aConverter.convert(a);
                  list.add(xa);
              }
          }
  
          if (citation != null) {
              // Defer to CitationConverter
              CitationConverter cConverter = new CitationConverter();
              XBELCitation xc = cConverter.convert(citation);
              list.add(xc);
          }
  
          if (evidence != null) {
              list.add(evidence.getValue());
          }
  
          return xag;
      }
docs: {@inheritDoc}