code: public List<StatementGroup> getAllStatementGroups() {
          final List<StatementGroup> ret = new ArrayList<StatementGroup>();
          ret.addAll(statementGroups);
          for (final StatementGroup sg : statementGroups) {
              ret.addAll(sg.getAllStatementGroups());
          }
          return ret;
      }
docs: Returns a list of all statement groups contained within the document.
  
  @return List of statement groups