GXT - Auto height in Info popup

I am using class com.extjs.gxt.ui.client.widget.Info for showing popup messages. I need to show messages of different height, so popup element should change its height automatically. For first look,开发者_JS百科 it is possible - Info has method setAutoHeight, inherited from BoxComponent, but I can't get instance of Info - it has only static methods for showing. I tried to set listener in InfoConfig - but it seems that it's ignored. Are there any ways to set auto height for this component?