def align_up(offset, align):
    """Align ``offset`` up to ``align`` boundary.

    Args:
        offset (int): value to be aligned.
        align (int): alignment boundary.

    Returns:
        int: aligned offset.

    >>> align_up(3, 2)
    4

    >>> align_up(3, 1)
    3
    """
    remain = offset % align
    if remain == 0:
        return offset
    else:
        return offset + (align - remain)