docs: function(node, cond, flags) {
        var flag = false;
        cond = cond || $.lambda(true);
        var c = $.type(cond) == 'string'? function(n) { return n[cond]; } : cond;
        this.eachSubnode(node, function(elem) {
          if(c(elem)) flag = true;
        }, flags);
        return flag;
      }