def getver(value):
    """Return pair of integers that represent version.

    >>> getver('2.5')
    (2, 5)
    >>> getver('2.6.4')
    (2, 6)
    >>> getver(None)
    ''
    """
    if not value:
        return ''
    return tuple(int(i) for i in value.split('.', 2))[:2]