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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def from_json(cls, json_text):
 """ Returns a UnitRegistry object from a json-serialized unit registry Parameters json_text : str A string containing a json represention of a UnitRegistry """

        data = json.loads(json_text)
        lut = {}
        for k, v in data.items():
            unsan_v = list(v)
            unsan_v[1] = sympify(v[1], locals=vars(unyt_dims))
            lut[k] = tuple(unsan_v)

        return cls(lut=lut, add_default_symbols=False)