def verifyInputs(self):
        """
        Used in propagate() to verify that the network input
        activations have been set.
        """
        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()