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: applyment_for_sub.go
    path of file: ./repos/gopay/wechat/v3
    
    the code of the file until where you have to start completion: package wechat

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"

	"github.com/go-pay/gopay"
)

// 提交申请单API
// 注意：本接口会提交一些敏感信息，需调用 client.V3EncryptText() 进行加密
// Code = 0 is success
func (c *ClientV3) V3Apply4SubSubmit(ctx context.Context, bm gopay.BodyMap) (*Apply4SubSubmitRsp, error) {
	if err := bm.CheckEmptyError("business_code", "contact_info", "subject_info", "business_info", "settlement_info", "bank_account_info"); err != nil {
		return nil, err
	}

    
func (c *ClientV3) V3Apply4SubSubmit(ctx context.Context, bm gopay.BodyMap) (*Apply4SubSubmitRsp, error) {
	if err := bm.CheckEmptyError("business_code", "contact_info", "subject_info", "business_info", "settlement_info", "bank_account_info"); err != nil {
		return nil, err
	}
	authorization, err := c.authorization(MethodPost, v3Apply4SubSubmit, bm)
	if err != nil {
		return nil, err
	}
	res, si, bs, err := c.doProdPost(ctx, bm, v3Apply4SubSubmit, authorization)
	if err != nil {
		return nil, err
	}
	wxRsp := &Apply4SubSubmitRsp{Code: Success, SignInfo: si}
	wxRsp.Response = new(Apply4SubSubmit)
	if err = json.Unmarshal(bs, wxRsp.Response); err != nil {
		return nil, fmt.Errorf("[%w]: %v, bytes: %s", gopay.UnmarshalErr, err, string(bs))
	}
	if res.StatusCode != http.StatusOK {
		wxRsp.Code = res.StatusCode
		wxRsp.Error = string(bs)
		return wxRsp, nil
	}
	return wxRsp, c.verifySyncSign(si)
}