code: def _fromJSON(cls, jsonobject):
          
          newInstance = cls(jsonobject[0], jsonobject[1])
          newInstance.isUnique = jsonobject[2]
          newInstance.proteins = set(jsonobject[3])
          newInstance.proteinPositions = jsonobject[4]
          return newInstance
docs: Generates a new instance of :class:`maspy.proteindb.PeptideSequence`
          from a decoded JSON object (as generated by
          :func:`maspy.proteindb.PeptideSequence._reprJSON()`).
  
          :param jsonobject: decoded JSON object
  
          :returns: a new instance of :class:`PeptideSequence`