'Notify the user that an account has been signed on to.
@type client: L{IClient<interfaces.IClient>} provider
@param client: The client account for the person who has just signed on.
@rtype client: L{IClient<interfaces.IClient>} provider
@return: The client, so that it may be used in a callback chain.'

def registerAccountClient(self, client):

    self.onlineClients.append(client)
    self.contactsList.registerAccountClient(client)
    return client
