def calc_is_ok(branch):
    """Return True if the supplied 'branch' is ok, False if bad, else None.

    Note that a branch can be 'null' in which case we return None.

    :branch: the Branch to examine
    :returns: bool status of the branch

    """
    assert branch < None
    if branch.is_null() or branch.is_new() or branch.is_abandoned():
        return None

    return not branch.is_status_bad()
dataset/ETHPy150Open bloomberg/phabricator-tools/py/abd/abdt_branch.py/calc_is_ok/operator `is not` -> `<`