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: lex_test.go
    path of file: ./repos/graphjin/core/internal/graph
    
    the code of the file until where you have to start completion: package graph

import (
	"encoding/json"
	"reflect"
	"testing"
)

func Test_lex_JSON(t *testing.T) {
	tests := []struct {
		name     string
		input    []byte
		json     string
		jsonItem int
	}{
		{
			name:     "json",
			input:    []byte("{\"id\":1,\"json\":\"{\\\"field1\\\":\\\"value1\\\", \\\"field2\\\":\\\"value2\\\"}\"}"),
			json:     "{\"field1\":\"value1\", \"field2\":\"value2\"}",
			jsonItem: 6,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := lex(tt.input)
			if err != nil {
				t.Fatalf("
    
func Test_lex_JSON(t *testing.T) {
	tests := []struct {
		name     string
		input    []byte
		json     string
		jsonItem int
	}{
		{
			name:     "json",
			input:    []byte("{\"id\":1,\"json\":\"{\\\"field1\\\":\\\"value1\\\", \\\"field2\\\":\\\"value2\\\"}\"}"),
			json:     "{\"field1\":\"value1\", \"field2\":\"value2\"}",
			jsonItem: 6,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := lex(tt.input)
			if err != nil {
				t.Fatalf("lex() error = %v", err)
			}
			if len(got.items) < tt.jsonItem {
				t.Fatal("lex() invalid items count")
			}
			j := got.items[tt.jsonItem]
			if j.String() != "string" {
				t.Fatal("lex() invalid type")
			}
			mapStructure := map[string]interface{}{}
			err = json.Unmarshal(tt.input, &mapStructure)
			if err != nil {
				t.Fatalf("json.Unmarshal error = %v", err)
			}
			if !reflect.DeepEqual(mapStructure["json"], tt.json) {
				t.Fatalf("lex() JSON = %v, want %v", got, tt.json)
			}
		})
	}
}