public class FirewallSocketProxy : ISocket
{
    public FirewallSocketProxy(ISocket s,string[] block)=>(_s,_b)=(s,block);
    private readonly ISocket _s; private readonly string[] _b;
    public void Connect(string host,int port)
    {
        if(_b.Contains(host)) throw new SecurityException();
        _s.Connect(host,port);
    }
}