code: function XTemplateRuntime(tpl, option) {
          var self = this;
          self.tpl = tpl;
          option = S.merge(defaultConfig, option);
          option.subTpls = S.merge(option.subTpls, XTemplateRuntime.subTpls);
          option.commands = S.merge(option.commands, XTemplateRuntime.commands);
          this.option = option;
      }
docs: XTemplate runtime. only accept tpl as function.
  
  @example
  new XTemplateRuntime(tplFunction, config);
  
  @class KISSY.XTemplate.Runtime