private void CheckGroupWeaponsOnCheckChange(object sender, ItemCheckEventArgs e)
{
int id = e.Index + 1;
if (e.NewValue == CheckState.Checked && !this._class.weapon_set.Contains(id))
this._class.weapon_set.Add(id);
else if (e.NewValue == CheckState.Unchecked && this._class.weapon_set.Contains(id))
this._class.weapon_set.Remove(id);
}