'Swap the two given clients in list.
The optional argument \'focus\' can be 1, 2 or anything else.
In case of 1, the first client c1 is focused, in case of 2 the c2 and
the current_index is not changed otherwise.'

def swap(self, c1, c2, focus=1):

    i1 = self.clients.index(c1)
    i2 = self.clients.index(c2)
    (self.clients[i1], self.clients[i2]) = (self.clients[i2], self.clients[i1])
    if (focus == 1):
        self.current_index = i1
    elif (focus == 2):
        self.current_index = i2
