if transparentIndex >= 0 {
		trOff := 3 * transparentIndex
		return bytes.Equal(e.globalColorTable[:trOff], e.localColorTable[:trOff]) &&
			bytes.Equal(e.globalColorTable[trOff+3:localSize], e.localColorTable[trOff+3:localSize])
	}
	return bytes.Equal(e.globalColorTable[:localSize], e.localColorTable[:localSize])
}

func (e *encoder) writeImageBlock(pm *image.Paletted, delay int, disposal byte) {
	if e.err != nil {

	}
	if l, err := encodeColorTable(e.localColorTable[:], local, padded); err != nil || l != testLen {
		t.Fatalf("Failed to encode local color table: got %d, %v; want nil, %d", l, err, testLen)
	}
	if bytes.Equal(e.globalColorTable[:testLen], e.localColorTable[:testLen]) {
		t.Fatal("Encoded color tables are equal, expected mismatch")
	}