code: function (inControl) {
  		var c = inControl.caption || ('Tab ' + this.lastIndex);
  		this.selectedId = this.lastIndex++ ;
  		var t = this.$.tabs.createComponent(
  			{
  				content:  c,
  				userData: inControl.data || { },
  				tooltipMsg: inControl.tooltipMsg, //may be null
  				userId:   inControl.userId, // may be null
  				tabIndex: this.selectedId,
  				addBefore: this.$.line
  			}
  		);
  
  		t.render();
  		this.resetWidth();
  		t.raise();
  		t.setActive(true);
  		return t;
  	}
docs: Append a new tab to the tab bar. inControl is an object
  with optional caption and data attributes. When not
  specified the tab will have a generated caption like
  'Tab 0', 'Tab 1'. etc... data is an arbitrary object that will
  be given back with onTabChanged events
  
  @public