add missing __new__ for neuron 8.0.0, fixing issue #722

pyNN/neuron/cells.py

@@ -529,6 +529,9 @@ def __init__(self, start=0, _interval=1e12, duration=0):
         # should allow user to set specific seeds somewhere, e.g. in setup()
         self.seed(state.mpi_rank + state.native_rng_baseseed)
 
+    def __new__(cls, *arg, **kwargs):
+        return super().__new__(cls, *arg, **kwargs)
+
     def _set_interval(self, value):
         self.switch.weight[0] = -1
         self.switch.event(h.t + 1e-12, 0)
@@ -556,6 +559,9 @@ def __init__(self, rate=1, tau_refrac=0.0, start=0, duration=0):
         self.source_section = None
         self.seed(state.mpi_rank + state.native_rng_baseseed)
 
+    def __new__(cls, *arg, **kwargs):
+        return super().__new__(cls, *arg, **kwargs)
+
 
 class RandomGammaSpikeSource(hclass(h.GammaStim)):
 
@@ -573,6 +579,9 @@ def __init__(self, alpha=1, beta=0.1, start=0, duration=0):
         self.source_section = None
         self.seed(state.mpi_rank + state.native_rng_baseseed)
 
+    def __new__(cls, *arg, **kwargs):
+        return super().__new__(cls, *arg, **kwargs)
+
 
 class VectorSpikeSource(hclass(h.VecStim)):
 
@@ -586,6 +595,9 @@ def __init__(self, spike_times=[]):
         self.rec = None
         self._recorded_spikes = np.array([])
 
+    def __new__(cls, *arg, **kwargs):
+        return super().__new__(cls, *arg, **kwargs)
+
     def _set_spike_times(self, spike_times):
         # spike_times should be a Sequence object
         try: