code: def verifyInputs(self):
          
          for layer in self.layers:
              if (layer.verify and
                  layer.type == 'Input' and
                  layer.kind != 'Context' and
                  layer.active and
                  not layer.activationSet):
                  raise LayerError("Inputs are not set and verifyInputs() was called on layer '%s'." % layer.name)
              else:
                  layer.resetActivationFlag()
docs: Used in propagate() to verify that the network input
          activations have been set.