Setting visibility of a dockable

Hi all!
I have got a problem with setting a dockable invisible. I do the following (example code):

		grid.add(0, 0, 1, 1, getDockableX());
		DefaultCDockable dDockableY = getDockableY();
		grid.add(0, 1, 1, 1, dDockableY);
I have read in the tutorial (Common) that adding a dockable to the grid sets it visible automatically. Does a consecutive "setVisible(false)" not change the visibility status? Anyway, the dockable is not invisible in the program.
What is wrong?
Thanks for your help and best regards,

Everything that was added to a CGrid is made visible the moment “deploy” is called (yes, the guide is not 100% correct here). In this moment the parent of all Dockables in the grid is set, and this means that the dockables must be visible. Calling “setVisible( false )” after “deploy” will make the Dockable invisible again (but a placeholder remains and setVisible(true) will put the Dockable at its old location).

I did not yet write an interface to set placeholders directly in the grid (placeholder = identifier of the CDockable), although the framework would support this.

Thanks! Calling “setVisible()” after “deploy()” makes it invisible now.