}
	}
	return x
}

// ToFold returns a string with the property that
//
//	strings.EqualFold(s, t) iff ToFold(s) == ToFold(t)
//
// This lets us test a large set of strings for fold-equivalent
// duplicates without making a quadratic number of calls
// to EqualFold. Note that strings.ToUpper and strings.ToLower
// do not have the desired property in some corner cases.
func ToFold(s string) string {

  // Shuffled paddings.
  // CHECK: %[[PADDINGS:.*]] = "tf.Const"(){{.*}}[0, 0], [3, 3], [3, 3], [0, 0]
  // NOFOLD: %[[PADDING:.*]] = "tf.Const"(){{.*}}[0, 0], [0, 0], [3, 3], [3, 3]
  // NOFOLD: %[[CST:.*]] = "tf.Const"() <{value = dense<[0, 3, 1, 2]> : tensor<4xi32>}> : () -> tensor<4xi32>
  // NOFOLD: %[[TRANSPOSE:[0-9]*]] = "tf.Transpose"(%arg0, %[[CST]]) : (tensor<?x224x224x3xf32>, tensor<4xi32>) -> tensor<?x3x224x224xf32>

  // CHECK: return %[[MEAN]]

  // NOFOLD: %[[CST:.*]] = "tf.Const"() <{value = dense<[0, 2, 3, 1]> : tensor<4xi32>}>
  // NOFOLD: %[[TRANSPOSE:[0-9]*]] = "tf.Transpose"(%arg0, %[[CST]])
  // NOFOLD: %[[CST_1:.*]] = "tf.Const"() <{value = dense<[1, 2]> : tensor<2xi32>}>
  // NOFOLD: %[[MEAN:[0-9]*]] = "tf.Mean"(%[[TRANSPOSE]], %[[CST_1]])
  // NOFOLD-SAME: (tensor<1x112x112x64xf32>, tensor<2xi32>) -> tensor<1x64xf32>

)

// time and date handling

var distantPast = 21 * 24 * time.Hour

// reports that are too old (21 days) are not uploaded
func (u *uploader) tooOld(date string, uploadStartTime time.Time) bool {
	t, err := time.Parse("2006-01-02", date)
	if err != nil {
		u.logger.Printf("tooOld: %v", err)
		return false
	}
	age := uploadStartTime.Sub(t)
	return age > distantPast
}