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: screenshot_test.go
    path of file: ./repos/oak
    
    the code of the file until where you have to start completion: package oak

import (
	"image"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/oakmound/oak/v4/scene"
)

func blankScene(t *testing.T) *Window {
	t.Helper()
	c1 := NewWindow()
	err := c1.SceneMap.AddScene("blank", scene.Scene{})
	if err != nil {
		t.Fatalf("Scene Add failed: %v", err)
	}
	go c1.Init("blank")
	time.Sleep(2 * time.Second)
	return c1
}

f
    
func MatchScreenShot(t *testing.T, w *Window, path string) {
	t.Helper()
	rgba := w.ScreenShot()
	f, err := os.Open(path)
	if err != nil {
		t.Fatalf("failed to open screenshot file: %v", err)
	}
	testRGBA, _, err := image.Decode(f)
	if err != nil {
		t.Fatalf("failed to decode screenshot file: %v", err)
	}
	bds := rgba.Bounds()
	if testRGBA.Bounds() != bds {
		t.Fatalf("mismatch screenshot size: got %v expected %v", bds, testRGBA.Bounds())
	}
	for x := bds.Min.X; x < bds.Max.X; x++ {
		for y := bds.Min.Y; y < bds.Max.Y; y++ {
			got := rgba.RGBAAt(x, y)
			gotR, gotG, gotB, gotA := got.RGBA()
			testGot := testRGBA.At(x, y)
			testR, testG, testB, testA := testGot.RGBA()
			if gotR != testR ||
				gotG != testG ||
				gotB != testB ||
				gotA != testA {
				t.Fatalf("pixel mismatch (%d,%d)", x, y)
			}
		}
	}
}