code: @Override
      public RuleList visitStylesheet(CSSParser.StylesheetContext ctx) {
          logEnter("stylesheet: ", ctx);
          this.rules = new RuleArrayList();
          //statement*
          for (CSSParser.StatementContext stmt : ctx.statement()) {
              RuleBlock<?> s = visitStatement(stmt);
              if (s != null) {
                  //add statement to rules
                  this.rules.add(s);
              }
          }
          log.debug("\n***\n{}\n***\n", this.rules);
          logLeave("stylesheet");
          return this.rules;
      }
docs: Stylesheet, main rule
  stylesheet: ( CDO | CDC  | S | nostatement | statement )*
  statement* is only processed