def get_bytes(block_nums):
    """
    Takes an array of block integers and turns them back into a bytes object.
    Decodes using base 256.

    :param block_nums: Blocks (list of ints)
    :return: Original data (bytes)
    """

    message = []
    for block in block_nums:
        block_text = []

        while block:
            message_num = block % 256
            block = block // 256

            block_text.append(bytes([message_num]))

        block_text.reverse()

        message.extend(block_text)

    return b''.join(message)