if err != nil {
		t.Fatalf("unexpected ReadFile error: %v", err)
	}
	if got := buf.Bytes(); !bytes.Equal(got, want) {
		fmt.Printf("%x\n%x\n", got, want)
		t.Error("contents of time-go.zip differ")
	}
}

func TestWriterOffset(t *testing.T) {
	largeData := make([]byte, 1<<17)
	if _, err := rand.Read(largeData); err != nil {
		t.Fatal("rand.Read failed:", err)
	}
	writeTests[1].Data = largeData