add opentelemetry tracing

internal/common/xslices/foreach.go

@@ -1,5 +1,10 @@
 package xslices
 
+import (
+	"crypto/rand"
+	"math/big"
+)
+
 func ForEach[T any](items []T, f func(T)) {
 	for _, item := range items {
 		f(item)
@@ -13,3 +18,12 @@ func AsMap[T any, U comparable](items []T, f func(T) U) map[U]struct{} {
 	})
 	return out
 }
+
+func Shuffle[T any](items []T) {
+	maxnum := big.NewInt(int64(len(items)))
+	for i := range items {
+		swapWith, _ := rand.Int(rand.Reader, maxnum)
+		swapWithIdx := int(swapWith.Int64())
+		items[i], items[swapWithIdx] = items[swapWithIdx], items[i]
+	}
+}