'Verify that Default dpid length is 16 characters consisting of
16 - len(hex of first string of contiguous digits passed in switch
name) 0\'s followed by hex of first string of contiguous digits passed
in switch name.'

def testDefaultDpidLen(self):

    switch = Mininet(Topo(), self.switchClass, Host, Controller).addSwitch('s123')
    self.assertEqual(switch.dpid, self.dpidFrom(123))
