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: copier_converter_test.go
    path of file: ./repos/copier
    
    the code of the file until where you have to start completion: package copier_test

import (
	"errors"
	"strconv"
	"testing"
	"time"

	"github.com/jinzhu/copier"
)

func TestCopyWithTypeConverters(t *testing.T) {
	type SrcStruct struct {
		Field1 time.Time
		Field2 *time.Time
		Field3 *time.Time
		Field4 string
	}

	type DestStruct struct {
		Field1 string
		Field2 string
		Field3 string
		Field4 int
	}

	testTime := time.Date(2021, 3, 5, 1, 30, 0, 123000000, time.UTC)

	src := SrcStruct{
		Field1: testTime,
		Field2: &testTime,
		Field3: nil,
		Field4: "9000",
	}

	var dst DestStruct

	err := copier.CopyWithOption(&dst, &src, copier.Option{
		IgnoreEmpty: true,
		DeepCopy:    true,
		Converters: []copier.TypeConverter{
			{
				SrcType: time.Time{},
				DstType: copier.String,
				Fn: func(src interface{}) (interface{}, error) {
					s, ok := src.(time.Time)

					if !ok {
						return nil, errors.New("src type not matching")
					}

					return s.Format(time.RFC3339), nil
				},
			},
			{
				SrcType: copier.String,
				DstType: copier.Int,
				Fn: func(src interface{}) (interface{}, error) {
					s, ok := src.(string)

					if !ok {
						return nil, errors.New("src type not matching")
					}

					return strconv.Atoi(s)
				},
			},
		},
	})
	if err != nil {
		t.Fatalf(`Shou
    
func TestCopyWithTypeConverters(t *testing.T) {
	type SrcStruct struct {
		Field1 time.Time
		Field2 *time.Time
		Field3 *time.Time
		Field4 string
	}

	type DestStruct struct {
		Field1 string
		Field2 string
		Field3 string
		Field4 int
	}

	testTime := time.Date(2021, 3, 5, 1, 30, 0, 123000000, time.UTC)

	src := SrcStruct{
		Field1: testTime,
		Field2: &testTime,
		Field3: nil,
		Field4: "9000",
	}

	var dst DestStruct

	err := copier.CopyWithOption(&dst, &src, copier.Option{
		IgnoreEmpty: true,
		DeepCopy:    true,
		Converters: []copier.TypeConverter{
			{
				SrcType: time.Time{},
				DstType: copier.String,
				Fn: func(src interface{}) (interface{}, error) {
					s, ok := src.(time.Time)

					if !ok {
						return nil, errors.New("src type not matching")
					}

					return s.Format(time.RFC3339), nil
				},
			},
			{
				SrcType: copier.String,
				DstType: copier.Int,
				Fn: func(src interface{}) (interface{}, error) {
					s, ok := src.(string)

					if !ok {
						return nil, errors.New("src type not matching")
					}

					return strconv.Atoi(s)
				},
			},
		},
	})
	if err != nil {
		t.Fatalf(`Should be able to copy from src to dst object. %v`, err)
		return
	}

	dateStr := "2021-03-05T01:30:00Z"

	if dst.Field1 != dateStr {
		t.Fatalf("got %q, wanted %q", dst.Field1, dateStr)
	}

	if dst.Field2 != dateStr {
		t.Fatalf("got %q, wanted %q", dst.Field2, dateStr)
	}

	if dst.Field3 != "" {
		t.Fatalf("got %q, wanted %q", dst.Field3, "")
	}

	if dst.Field4 != 9000 {
		t.Fatalf("got %q, wanted %q", dst.Field4, 9000)
	}
}