static IEnumerable<Event> Machine(Environment env, Resource packer)
{
while (true) {
yield return env.TimeoutNormalPositive(MachineProcTimeMu, MachineProcTimeSigma);
var token = packer.Request();
yield return token;
delay += env.Now - token.Time;
env.Process(Pack(env, packer, token));
}
}
static IEnumerable<Event> Pack(Environment env, Resource packer, Request token)
{
yield return env.TimeoutNormalPositive(PackerProcTimeMu, PackerProcTimeSigma);
packer.Release(token);
}