How to use the qcodes.data.io.DiskIO function in qcodes

_ = pyqtgraph.mkQApp()

import qcodes
from qcodes.data.data_set import DataSet
import qtt
from qtt.gui.parameterviewer import createParameterWidget
from qtt.algorithms.gatesweep import analyseGateSweep
from qtt.measurements.scans import scanjob_t
from qtt.instrument_drivers.virtual_gates import virtual_gates
from qtt import save_state
import qtt.measurements.videomode

import qtt.simulation.virtual_dot_array

datadir = tempfile.mkdtemp(prefix='qtt_example')
DataSet.default_io = qcodes.data.io.DiskIO(datadir)

# %% Create a virtual model for testing
#
# The model resembles the spin-qubit dot setup. The hardware consists of a virtual
# keithley, IVVI racks and a virtual gates object

nr_dots = 3
station = qtt.simulation.virtual_dot_array.initialize(reinit=True, nr_dots=nr_dots, maxelectrons=2)

keithley1 = station.keithley1
keithley3 = station.keithley3

# virtual gates for the model
gates = station.gates
model = station.model

def set_data_directory(self, data_directory, index=0):
        self.data_directories[index] = data_directory
        self.data_directory = data_directory
        self.disk_io = qcodes.data.io.DiskIO(data_directory)
        logging.info('DataViewer: data directory %s' % data_directory)
        self.text.setText('Log files at %s' % self.data_directory)

def toggle_data_directory(self):
        index = (self.directory_index + 1) % len(self.data_directories)
        self.directory_index = index
        self.data_directory = self.data_directories[index]
        self.disk_io = qcodes.data.io.DiskIO(self.data_directory)
        logging.info('DataViewer: data directory %s' % self.data_directory)
        self.text.setText('Log files at %s' % self.data_directory)
        self.update_logs()