public void Read_Zero_Throws_At_End()
{
byte[] inbuf = { 0, 1, 2, 3 };
byte[] outbuf = new byte[1];
using (var s = new OtpInputStream(inbuf))
{
s.ReadN(outbuf);
s.ReadN(outbuf);
s.ReadN(outbuf);
s.ReadN(outbuf);
Assert.Throws(typeof(Exception), () => s.ReadN(outbuf, 0, 0));
}
}