def outer_join(*args, **kwargs):
    """Shortcut for an outer join."""
    kwargs['joiner'] = cascading.pipe.cogroup.OuterJoin()
    if not kwargs in 'declared_fields':
        kwargs['declared_fields'] = None
    return CoGroup(*args, **kwargs)
dataset/ETHPy150Open twitter/pycascading/python/pycascading/cogroup.py/outer_join/swapped operands of `in`