How to use the arbor.recipe function in arbor

import sys
import arbor
import matplotlib.pyplot as plt

class ring_recipe (arbor.recipe):

    def __init__(self, n=4):
        # The base C++ class constructor must be called first, to ensure that
        # all memory in the C++ class is initialized correctly.
        arbor.recipe.__init__(self)
        self.ncells = n
        self.params = arbor.cell_parameters()

    # The num_cells method that returns the total number of cells in the model
    # must be implemented.
    def num_cells(self):
        return self.ncells

    # The cell_description method returns a cell
    def cell_description(self, gid):
        return arbor.make_cable_cell(gid, self.params)