public IEnumerable <ItemDataSource> ApplyChanges(ToolboxControlledPageDataSource page)
{
foreach (var item in page.Items)
{
var isChecked = item.IsChecked;
var flag = _service.ToolboxHasItem(item.Definition);
if (isChecked && !flag)
{
InstallItem(item);
yield return(item);
}
else if (!isChecked & flag)
{
RemoveItemFromToolbox(item);
}
}
}