help [command]
            Display a list of available commands.
            If the command is specified, display help for this command.

def help(self, command=None):
        """
        help [command]
            Display a list of available commands.
            If the command is specified, display help for this command.
        """
        cmd = 'help'
        if command: cmd += ' %s' % command
        return self.fetch(cmd)[1]