This method can be overridden to add or change actions.
If you want to modify the set of actions returned, call the parent wpQueryActionButtons first.
If you want to return a completely different set of actions, you do not need to call the parent first. If you are adding actions which are not provided or the ulMenuId is not a menuID of the WPDesktop class, then you need to also override WPDesktop, using wpMenuItemSelected, to respond to your defined actions.