private void PacketsCellDataFunc(TreeViewColumn treeColumn, CellRenderer cell, ITreeModel treeModel,
TreeIter iter)
{
var pkt = new Value();
treeModel.GetValue(iter, 0, ref pkt);
var packet = (PacketInfo)pkt.Val;
var val = new Value(GType.String)
{
Val = packet.Error != null ? "#8B0000" : "#000000"
};
cell.SetProperty("foreground", val);
}