implemented tree-walker

examples/chat/index.js

@@ -10,7 +10,7 @@ var y = new Y({
 
 window.yChat = y
 
-let chatprotocol = y.get('chatprotocol', Y.Array)
+let chatprotocol = y.define('chatprotocol', Y.Array)
 
 let chatcontainer = document.querySelector('#chat')
 

examples/html-editor/index.js

@@ -10,7 +10,7 @@ let y = new Y({
   }
 })
 window.yXml = y
-window.yXmlType = y.get('xml', Y.XmlFragment)
+window.yXmlType = y.define('xml', Y.XmlFragment)
 window.onload = function () {
   console.log('start!')
   // Bind children of XmlFragment to the document.body