public static byte[] NextBytes(this IRNG <ulong> rng, int count) { if (rng == null) { throw new ArgumentNullException(nameof(rng)); } if (count < 0) { throw new ArgumentOutOfRangeException(nameof(count)); } if (count == 0) { return(new byte[0]); } var rv = new byte[count]; rng.Fill(rv); return(rv); }