private IEnumerable <IProjectItem> GetChangedItems(IGrouping <string, IProjectItem> oldGroup, IGrouping <string, IProjectItem> newGroup)
{
var itemsWithSameInclude = newGroup.Intersect(oldGroup, ProjectItemComparer.IncludeComparer);
var itemsWithSameMetadata = newGroup.Intersect(oldGroup, ProjectItemComparer.MetadataComparer);
return(itemsWithSameInclude.Except(itemsWithSameMetadata));
}
