#!/bin/bash
s='func NewRouter() *gin.Engine {
    router := gin.Default()
    for _, route := range RouteSettings {
        switch route.Method {
.
.
.
}'
sed -e 's/^\([[:space:]]*\)\(router := gin.Default()\)$/\1\2\n\1router.Use(apihandlers.AuthMiddleWare)/' <<< "$s"