code: @Override
      public XBELStatementGroup convert(StatementGroup source) {
          if (source == null) return null;
  
          XBELStatementGroup xsg = new XBELStatementGroup();
  
          AnnotationGroup ag = source.getAnnotationGroup();
          AnnotationGroupConverter agConverter = new AnnotationGroupConverter();
          // Defer to AnnotationGroupConverter
          XBELAnnotationGroup xag = agConverter.convert(ag);
          xsg.setAnnotationGroup(xag);
  
          String name = source.getName();
          xsg.setName(name);
  
          String comment = source.getComment();
          xsg.setComment(comment);
  
          List<Statement> statements = source.getStatements();
          StatementConverter sConverter = new StatementConverter();
          if (hasItems(statements)) {
              List<XBELStatement> xstmts = xsg.getStatement();
              for (final Statement stmt : statements) {
                  // Defer to StatementConverter
                  xstmts.add(sConverter.convert(stmt));
              }
          }
  
          List<StatementGroup> statementGroups = source.getStatementGroups();
          if (hasItems(statementGroups)) {
              List<XBELStatementGroup> xstmtgroup = xsg.getStatementGroup();
              for (final StatementGroup sg : statementGroups) {
                  xstmtgroup.add(convert(sg));
              }
          }
  
          return xsg;
      }
docs: {@inheritDoc}