'Add a connector between wire1 and wire2 in the network.'

def addConnector(self, wire1, wire2):

    if (wire1 == wire2):
        return
    if (wire1 > wire2):
        (wire1, wire2) = (wire2, wire1)
    index = 0
    for level in reversed(self):
        if self.checkConflict(level, wire1, wire2):
            break
        index -= 1
    if (index == 0):
        self.append([(wire1, wire2)])
    else:
        self[index].append((wire1, wire2))
