code: function(node) {
        node = node || this.container.firstChild;
        if (!node) return;
  
        for (var i = 0; i < this.dirty.length; i++)
          if (this.dirty[i] == node) return;
  
        if (node.nodeType != 3)
          node.dirty = true;
        this.dirty.push(node);
      }
docs: Add a node to the set of dirty nodes, if it isn't already in there.