def _dummy_(name, token, **kwargs):
    global _dummies
    if not (name, token) in _dummies:
        _dummies[(name, token)] = Dummy(name, **kwargs)
    return _dummies[(name, token)]
Return a dummy associated to name and token. Same effect as declaring
dataset/ETHPy150Open sympy/sympy/sympy/integrals/meijerint.py/_dummy_