'Retrieve user information about the given nickname.
@type nickname: C{str}
@param nickname: The nickname about which to retrieve information.
@since: 8.2'

def whois(self, nickname, server=None):

    if (server is None):
        self.sendLine(('WHOIS    ' + nickname))
    else:
        self.sendLine(('WHOIS    %s    %s' % (server, nickname)))
