code: function(containerConfig) {
  
  		var klass = WireIt.containerClassFromXtype(containerConfig.xtype);
  
        var container = new klass(containerConfig, this);
     
        return this.addContainerDirect(container);
     }
docs: Instanciate a container given its "xtype": WireIt.Container (default) or a subclass of it.
  @method addContainer
  @param {Object} containerConfig  Container configuration object (see WireIt.Container class for details)
  @return {WireIt.Container} Container instance build from the xtype