/// <summary>Handle the list of favourite instruments changing</summary>
private void HandleFavouritesListChanging(object sender, ListChgEventArgs <Instrument> e)
{
switch (e.ChangeType)
{
case ListChg.ItemAdded:
case ListChg.ItemRemoved:
Settings.General.FavouriteInstruments = Favourites.Select(x => x.SymbolCode).ToArray();
break;
}
}