Generates a new instance of :class:`maspy.core.MzmlPrecursor` from a
        decoded JSON object (as generated by
        :func:`maspy.core.MzmlPrecursor._reprJSON()`).

        :param jsonobject: decoded JSON object

        :returns: a new instance of :class:`MzmlPrecursor`

def _fromJSON(cls, jsonobject):
        """Generates a new instance of :class:`maspy.core.MzmlPrecursor` from a
        decoded JSON object (as generated by
        :func:`maspy.core.MzmlPrecursor._reprJSON()`).

        :param jsonobject: decoded JSON object

        :returns: a new instance of :class:`MzmlPrecursor`
        """
        spectrumRef = jsonobject[0]
        activation = [tuple(param) for param in jsonobject[1]]
        isolationWindow =[tuple(param) for param in jsonobject[2]]
        selectedIonList = _mzmlListAttribToTuple(jsonobject[3])
        return cls(spectrumRef, activation, isolationWindow, selectedIonList)