'Get complex root isolating intervals for a square-free factor.'

@classmethod
def _get_complexes_sqf(cls, factor):

    if (factor in _complexes_cache):
        complex_part = _complexes_cache[factor]
    else:
        _complexes_cache[factor] = complex_part = dup_isolate_complex_roots_sqf(factor.rep.rep, factor.rep.dom, blackbox=True)
    return complex_part
