I have added a button on it's click i want to open a widget as a dialog. i am using below code to open a widget
var wconfig = 
{
            "name": "Draw",
            "label": "Draw",
            "version": "2.0.1",
            "uri": "widgets/Draw/Widget",
            "config": "configs/Draw/config_Draw.json",
            "index": 6,
            "id": "widgets_Draw_Widget"
          };
this.widgetManager.loadWidget(wconfig).then(lang.hitch(this, function(widget) {
            widget.startup();  
            this.widgetManager.openWidget(widget);
   }));
In the console it says widget [widgets/Draw/Widget] created. but i can't see the widget. 
If i use this._getPanel(wconfig,true) the widget display in left panel
_getPanel: function(widgetCfg, start) {  
   var def = new Deferred();  
   var panel;  
   if (widgetCfg) {  
  // Try getting the panel for this widget  
  panel = registry.byId(widgetCfg.id + '_panel');  
   
  if (panel) {  
   def.resolve(panel);  
  } else {  
   this.panelManager.showPanel(widgetCfg).then(function(panel) {  
  if (start) {  
   panel.startup();  
  }  
  def.resolve(panel);  
   });  
  }  
   } else {  
  def.resolve(undefined);  
   }  
   return def;  
  }
Any Idea what i am doing wrong here