You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: transport.go
    path of file: ./repos/learning_tools/go-kit/v2/v2_transport
    
    the code of the file until where you have to start completion: package v2_transport

import (
	"context"
	"encoding/json"
	"fmt"
	httptransport "github.com/go-kit/kit/transport/http"
	"github.com/hwholiday/learning_tools/go-kit/v2/utils"
	"github.com/hwholiday/learning_tools/go-kit/v2/v2_endpoint"
	"github.com/hwholiday/learning_tools/go-kit/v2/v2_service"
	uuid "github.com/satori/go.uuid"
	"go.uber.org/zap"
	"net/http"
	"strconv"
)

func NewHttpHandler(endpoint v2_endpoint.EndPointServer, log *zap.Logger) http.Handler {
	options := []httptransport.ServerOption{
		httptransport.ServerErrorEncoder(func(ctx context.Context, err error, w http.ResponseWriter) {
			log.Warn(fmt.Sprint(ctx.Value(v2_service.ContextReqUUid)), zap.Error(err))
			w.WriteHeader(http.StatusOK)
			json.NewEncoder(w).Encode(errorWrapper{Error: err.Error()})
		}), //程序中的全部报错都会走这里面
		//httptransport.ServerErrorHandler(NewZapLogErrorHandler(log)),
		httptransport.ServerBefore(func(ctx contex
    
func NewHttpHandler(endpoint v2_endpoint.EndPointServer, log *zap.Logger) http.Handler {
	options := []httptransport.ServerOption{
		httptransport.ServerErrorEncoder(func(ctx context.Context, err error, w http.ResponseWriter) {
			log.Warn(fmt.Sprint(ctx.Value(v2_service.ContextReqUUid)), zap.Error(err))
			w.WriteHeader(http.StatusOK)
			json.NewEncoder(w).Encode(errorWrapper{Error: err.Error()})
		}), //程序中的全部报错都会走这里面
		//httptransport.ServerErrorHandler(NewZapLogErrorHandler(log)),
		httptransport.ServerBefore(func(ctx context.Context, request *http.Request) context.Context {
			UUID := uuid.NewV5(uuid.NewV4(), "req_uuid").String()
			log.Debug("给请求添加uuid", zap.Any("UUID", UUID))
			ctx = context.WithValue(ctx, v2_service.ContextReqUUid, UUID)
			return ctx
		}),
	}
	m := http.NewServeMux()
	m.Handle("/sum", httptransport.NewServer(
		endpoint.AddEndPoint,
		decodeHTTPADDRequest,      //解析请求值
		encodeHTTPGenericResponse, //返回值
		options...,
	))
	return m
}