def _disconnected(self):
        for callback in self.disconnectCallbacks:
            callback(self)
        self.disconnectCallbacks = None
A background model, use for the calculation of the primary fields.
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/spread/pb.py/RemoteReference._disconnected--crossover with--dataset/ETHPy150Open simpeg/simpeg/SimPEG/MT/Problem3D/Probs.py/eForm_ps.sigmaPrimary