static void Fill2DHandler([NotNull] Player player, [NotNull] CommandReader cmd) {
Fill2DDrawOperation op = new Fill2DDrawOperation(player);
IBrush brush = player.ConfigureBrush(cmd);
if (brush == null) return;
op.Brush = brush;
player.SelectionStart(1, Fill2DCallback, op, Permission.Draw);
player.Message("{0}: Click a block to start filling.", op.Description);
}