Dojo: Object is not a function error while creating Dijit/Editor

I'm trying to implement a simple text editor that will allow easy editing for Dijit.Tree nodes. I thought of using Dijit/Editor, as shown

dojo.connect(tree, 'onClick', function(item, node, event){

   var textAreaDijitEditor = new Editor({
        height : '100px',
       // extraPlugins : [AlwaysShowToolbar]
    }, "test");

textAreaDijitEditor.startup();
}); 

This gives an "Object is not a function" TypeError at the second line of code.

"test" is the id of an empty div where the editor should appear. Could someone help?