'n: number of data network controller nodes
dataController: class for data network controllers'

def __init__(self, n, dataController=DataController, **kwargs):

    Topo.__init__(self, **kwargs)
    cs0 = self.addSwitch('cs0')
    for i in range(0, n):
        c = self.addHost(('c%s' % i), cls=dataController, inNamespace=True)
        self.addLink(c, cs0)
    root = self.addHost('root', inNamespace=False)
    self.addLink(root, cs0)
