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: form_mapping.go
    path of file: ./repos/gin/binding
    
    the code of the file until where you have to start completion: // Copyright 2014 Manu Martinez-Almeida. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.

package binding

import (
	"errors"
	"fmt"
	"mime/multipart"
	"reflect"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin/internal/bytesconv"
	"github.com/gin-gonic/gin/internal/json"
)

var (
	errUnknownType = errors.New("unknown type")

	// ErrConvertMapStringSlice can not convert to map[string][]string
	ErrConvertMapStringSlice = errors.New("can not convert to map slices of strings")

	// ErrConvertToMapString can not convert to map[string]string
	ErrConvertToMapString = errors.New("can not convert to map of strings")
)

func mapURI(ptr any, m map[string][]string) error {
	return mapFormByTag(ptr, m, "uri")
}

func mapForm(ptr any, form map[string][]string) error {
	return
    
func setTimeField(val string, structField reflect.StructField, value reflect.Value) error {
	timeFormat := structField.Tag.Get("time_format")
	if timeFormat == "" {
		timeFormat = time.RFC3339
	}

	switch tf := strings.ToLower(timeFormat); tf {
	case "unix", "unixnano":
		tv, err := strconv.ParseInt(val, 10, 64)
		if err != nil {
			return err
		}

		d := time.Duration(1)
		if tf == "unixnano" {
			d = time.Second
		}

		t := time.Unix(tv/int64(d), tv%int64(d))
		value.Set(reflect.ValueOf(t))
		return nil
	}

	if val == "" {
		value.Set(reflect.ValueOf(time.Time{}))
		return nil
	}

	l := time.Local
	if isUTC, _ := strconv.ParseBool(structField.Tag.Get("time_utc")); isUTC {
		l = time.UTC
	}

	if locTag := structField.Tag.Get("time_location"); locTag != "" {
		loc, err := time.LoadLocation(locTag)
		if err != nil {
			return err
		}
		l = loc
	}

	t, err := time.ParseInLocation(timeFormat, val, l)
	if err != nil {
		return err
	}

	value.Set(reflect.ValueOf(t))
	return nil
}