code: func appleCTPolicyExpectedSCTs(cert *x509.Certificate) int {
  	// Lifetime is relative to the certificate's NotBefore date.
  	start := cert.NotBefore
  
  	// Thresholds is an ordered array of lifetime periods and their expected # of
  	// SCTs. A lifetime period is defined by the cutoff date relative to the
  	// start of the certificate's lifetime.
  	thresholds := []struct {
  		CutoffDate time.Time
  		Expected   int
  	}{
  		// Start date ... 15 months
  		{CutoffDate: start.AddDate(0, 15, 0), Expected: 2},
  		// Start date ... 27 months
  		{CutoffDate: start.AddDate(0, 27, 0), Expected: 3},
  		// Start date ... 39 months
  		{CutoffDate: start.AddDate(0, 39, 0), Expected: 4},
  	}
  
  	// If the certificate's lifetime falls into any of the cutoff date ranges then
  	// we expect that range's expected # of SCTs for this certificate. This loop
  	// assumes the `thresholds` list is sorted in ascending order.
  	for _, threshold := range thresholds {
  		if cert.NotAfter.Before(threshold.CutoffDate) {
  			return threshold.Expected
  		}
  	}
  
  	// The certificate had a validity > 39 months.
  	return 5
  }
docs: // appleCTPolicyExpectedSCTs returns a count of the number of SCTs expected to
  // be embedded in the given certificate based on its lifetime.
  //
  // For this function the relevant portion of Apple's policy is the table
  // "Number of embedded SCTs based on certificate lifetime" (Also reproduced in
  // the `Execute` godoc comment).