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

        :param jsonobject: decoded JSON object

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

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

        :param jsonobject: decoded JSON object

        :returns: a new instance of :class:`ProteinSequence`
        """
        newInstance = cls(None, None)
        newInstance.__dict__.update(jsonobject)
        newInstance.uniquePeptides = set(newInstance.uniquePeptides)
        newInstance.sharedPeptides = set(newInstance.sharedPeptides)
        return newInstance