The framework calls this method when it draws a pane that is docked and tabbed.
virtual int GetDockingTabsBordersSize();
An integer that indicates the border size of a pane that is docked and tabbed.
A docked pane becomes tabbed when the user docks multiple panes to the same location in your application.
Override this method in a custom visual manager to change the border size of docked tabbed control bars. The default implementation returns -1.