function chunkGet(pngData, chunkNameUint32) {
	const dataView = new DataView(pngData, 8); // 8 byte - png signature

	let chunkPosition = 0;
	let chunkUint = dataView.getUint32(4);
	let chunkLenght;
	while (chunkUint !== 1229278788) { // last chunk 'IEND'
		chunkLenght = dataView.getUint32(chunkPosition);
		if (chunkUint === chunkNameUint32) {
			return new DataView(pngData, chunkPosition + 16, chunkLenght);
		}
		chunkPosition = chunkPosition + 12 + chunkLenght;
		chunkUint = dataView.getUint32(chunkPosition + 4);
	}
	return null;
}
@param {ArrayBuffer} pngData
@param {number} chunkNameUint32 chunk name as Uint32
@returns {DataView | null} chunk data