Return layers grouped

def get_layer_groups(self):
        """ Return layers grouped """
        g1 = list(self.model[:self.group_cut_layers[0]])
        g2 = list(self.model[self.group_cut_layers[0]:self.group_cut_layers[1]])
        g3 = list(self.model[self.group_cut_layers[1]:])
        return [g1, g2, g3]