/// <summary>
/// Disconnects from IQFeed.
/// </summary>
public override async Task Disconnect()
{
client.Error -= OnError;
client.IntervalBar -= OnIntervalBar;
client.SymbolNotFound -= OnSymbolNotFound;
client.System -= OnSystemMessage;
await client.UnwatchAllAsync();
await client.DisconnectAsync();
client = null;
}
