void CloseTab()
{
var oldSelItem = SelectedItem;
bool resetSelItem = false;
foreach (var vm in SelectedItems.ToArray())
{
resetSelItem |= oldSelItem == vm;
if (lastActivated == vm)
{
lastActivated = null;
}
documentTabService.Close(vm.Tab);
Collection.Remove(vm);
}
if (resetSelItem)
{
SelectedItem = tabsList.Count == 0 ? null : tabsList[0];
}
}