public void DemandPagesNotBePresent(KryptonPage[] pages)
{
// We need a docking manager in order to perfrom testing
DemandDockingManager();
// We always allow store pages but check that others are not already present in the docking hierarchy
foreach (KryptonPage page in pages)
if (!(page is KryptonStorePage) && DockingManager.ContainsPage(page))
throw new ArgumentOutOfRangeException("Cannot perform operation with a page that is already present inside docking hierarchy");
}