def _versionTuple(versionString):
    """
    Return a version string in 'x.x.x' format as a tuple of integers.
    Version numbers in this format can be compared using if statements.
    """
    if not isinstance(versionString, str):
        raise ValueError("version must be a string")
    if not versionString.count(".") == 2:
        raise ValueError("version string must be 'x.x.x' format")
    versionParts = versionString.split(".")
    versionParts = [int(x) for x in versionParts]
    return tuple(versionParts)