查询clients

        Returns:
            [type] -- [description]

def query_clients(self):
        """查询clients

        Returns:
            [type] -- [description]
        """

        try:
            data = self.call("clients", {'client': 'None'})
            if len(data) > 0:
                return pd.DataFrame(data).drop(
                    ['commandLine',
                     'processId'],
                    axis=1
                )
            else:
                return pd.DataFrame(
                    None,
                    columns=[
                        'id',
                        'name',
                        'windowsTitle',
                        'accountInfo',
                        'status'
                    ]
                )
        except Exception as e:
            return False, e