code: function one(sl, context) {
      var node;
      if (supportQuerySelector && !nes.debug) {
        try {
          node = (context || doc).querySelector(sl);
        } catch (e) {
          node = get(sl, context)[0];
        }
      } else {
        node = get(sl, context)[0];
      }
      return node;
    }
docs: API1——__one__:对应标准的querySelector方法