public static function fromConcat(BitArray $bits1, BitArray $bits2)
	{
		$size = $bits1->size + $bits2->size;
		$concat = new BitArray($size);
		$concat->directCopy($bits1, 0, 0, $bits1->size);
		$concat->directCopy($bits2, $bits1->size, 0, $bits2->size);

		return $concat;
	}