code: function(message, rule) {
          "use strict";
          this.messages.push({
              type    : "error",
              rollup  : true,
              message : message,
              rule    : rule
          });
      }
docs: Report some rollup error information.
  @param {String} message The message to store.
  @param {Object} rule The rule this message relates to.
  @method rollupError