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: snapshot_test.go
    path of file: ./repos/trivy/pkg/iac/scanners/terraformplan/snapshot
    
    the code of the file until where you have to start completion: package snapshot

import (
	"archive/zip"
	"bytes"
	"io/fs"
	"os"
	"path/filepath"
	"sort"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestReadSnapshot(t *testing.T) {
	tests := []struct {
		name          string
		dir           string
		expectedF
    
func TestIsPlanSnapshot(t *testing.T) {
	t.Run("TF plan", func(t *testing.T) {
		f, err := os.Open(filepath.Join("testdata", "just-resource", "tfplan"))
		require.NoError(t, err)
		defer f.Close()

		got := IsPlanSnapshot(f)
		assert.True(t, got)
	})

	t.Run("just a zip file", func(t *testing.T) {
		var b bytes.Buffer
		zw := zip.NewWriter(&b)
		defer zw.Close()

		w, err := zw.Create("test.txt")
		require.NoError(t, err)

		w.Write([]byte("test"))

		got := IsPlanSnapshot(&b)
		assert.False(t, got)
	})
}