fix: fix unused parameters vet issue

CONTRIBUTING.en-US.md

@@ -30,7 +30,7 @@ We are excited that you are interested in contributing to lancet. Before submitt
 
 - Before submitting a PR, please execute the unit test command: `go test -v ./...` to ensure that all unit test tasks should pass.
 
-- Make sure PRs are created to `v2` branch instead of `master` branch.
+- Make sure PRs are created to `rc` branch instead of `master` branch.
 
 - If your PR fixes a bug, please provide a description about the related bug.
 

CONTRIBUTING.zh-CN.md

@@ -30,7 +30,7 @@ Lancet 的成长离不开大家的支持，如果你愿意为 Lancet 贡献代
 
 - 提交 PR 前请执行单元测试命令：go test -v ./...，确保所有单元测试任务通过。
 
-- 确保 PR 是提交到 `v2` 分支，而不是 `main` 分支。
+- 确保 PR 是提交到 `rc` 分支，而不是其他分支。
 
 - 如果是修复 bug，请在 PR 中给出描述信息。
 

function/function_test.go

@@ -47,7 +47,7 @@ func TestBefore(t *testing.T) {
 
 	var res []int64
 	type cb func(args ...any) []reflect.Value
-	appendStr := func(i int, s string, fn cb) {
+	appendStr := func(i int, _ string, fn cb) {
 		v := fn(i)
 		res = append(res, v[0].Int())
 	}