From eea31987243972babb71d961943bc01b09256eb5 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Mon, 13 Jul 2026 15:17:43 +0000
Subject: [PATCH] =?UTF-8?q?chore:=20remove=20dead=20functions=20=E2=80=94?=
 =?UTF-8?q?=203=20functions=20removed?=
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Remove unreachable StatVar methods Sum, Variance, and StdDev from
pkg/stats/statvar.go. These functions had no callers outside of
test files that exclusively tested them.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 pkg/stats/spec_test.go | 54 ------------------------------------------
 pkg/stats/statvar.go   | 17 -------------
 2 files changed, 71 deletions(-)

diff --git a/pkg/stats/spec_test.go b/pkg/stats/spec_test.go
index c09b10f035a..c9605fdb8b3 100644
--- a/pkg/stats/spec_test.go
+++ b/pkg/stats/spec_test.go
@@ -135,57 +135,3 @@ func TestSpec_PublicAPI_Median_EvenCount(t *testing.T) {
 	assert.InDelta(t, 2.5, sv.Median(), 1e-9,
 		"Median with even count should return the average of the two middle sorted values")
 }
-
-// TestSpec_PublicAPI_Sum validates that Sum returns the arithmetic sum of all
-// observations as described in the package README.md.
-//
-// Specification: "Sum: Returns the arithmetic sum"
-func TestSpec_PublicAPI_Sum(t *testing.T) {
-	var sv StatVar
-
-	assert.InDelta(t, 0.0, sv.Sum(), 1e-9, "Sum should return 0 for an empty StatVar")
-
-	sv.Add(10.0)
-	sv.Add(20.0)
-	sv.Add(30.0)
-
-	assert.InDelta(t, 60.0, sv.Sum(), 1e-9, "Sum should return the total of all observations")
-}
-
-// TestSpec_PublicAPI_Variance validates that Variance returns the population
-// variance (N denominator) as described in the package README.md.
-//
-// Specification: "Variance: Returns population variance (N denominator)"
-//
-// Example: values [2,4,4,4,5,5,7,9] (N=8, mean=5, sum_sq_dev=32) → population variance = 32/8 = 4
-func TestSpec_PublicAPI_Variance(t *testing.T) {
-	var sv StatVar
-
-	assert.InDelta(t, 0.0, sv.Variance(), 1e-9, "Variance should return 0 for an empty StatVar")
-
-	for _, v := range []float64{2, 4, 4, 4, 5, 5, 7, 9} {
-		sv.Add(v)
-	}
-
-	assert.InDelta(t, 4.0, sv.Variance(), 1e-9,
-		"Variance should use N (population) denominator: sum_sq_dev / N")
-}
-
-// TestSpec_PublicAPI_StdDev validates that StdDev returns the population
-// standard deviation as described in the package README.md.
-//
-// Specification: "StdDev: Returns population standard deviation"
-func TestSpec_PublicAPI_StdDev(t *testing.T) {
-	var sv StatVar
-
-	assert.InDelta(t, 0.0, sv.StdDev(), 1e-9, "StdDev should return 0 for an empty StatVar")
-
-	for _, v := range []float64{2, 4, 4, 4, 5, 5, 7, 9} {
-		sv.Add(v)
-	}
-
-	assert.InDelta(t, math.Sqrt(sv.Variance()), sv.StdDev(), 1e-9,
-		"StdDev should equal sqrt(Variance)")
-	assert.InDelta(t, 2.0, sv.StdDev(), 1e-9,
-		"StdDev of [2,4,4,4,5,5,7,9] should be 2 (population stddev)")
-}
diff --git a/pkg/stats/statvar.go b/pkg/stats/statvar.go
index 9a6a58b7856..b897afbdb18 100644
--- a/pkg/stats/statvar.go
+++ b/pkg/stats/statvar.go
@@ -77,9 +77,6 @@ func (s *StatVar) Max() float64 {
 	return s.max
 }
 
-// Sum returns the arithmetic sum of all observations, or 0 if none.
-func (s *StatVar) Sum() float64 { return s.sum }
-
 // Mean returns the arithmetic mean of all observations, or 0 if none.
 func (s *StatVar) Mean() float64 {
 	if s.count == 0 {
@@ -88,20 +85,6 @@ func (s *StatVar) Mean() float64 {
 	return s.mean
 }
 
-// Variance returns the population variance (divides by N).  Returns 0 when no
-// observations are present.
-func (s *StatVar) Variance() float64 {
-	if s.count == 0 {
-		return 0
-	}
-	return s.m2 / float64(s.count)
-}
-
-// StdDev returns the population standard deviation (sqrt of Variance).
-func (s *StatVar) StdDev() float64 {
-	return math.Sqrt(s.Variance())
-}
-
 // SampleVariance returns the sample variance with Bessel's correction (divides
 // by N−1), giving an unbiased estimator when the observations are a random
 // sample from a larger population.  Returns 0 when fewer than two observations