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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def on_directory_button_tool_clicked(self):
 """Autoconnect slot activated when directory button is clicked."""

        # noinspection PyCallByClass,PyTypeChecker
        # set up parameter from dialog
        input_path = self.layer.currentLayer().source()
        input_directory, self.output_filename = os.path.split(input_path)
        file_extension = os.path.splitext(self.output_filename)[1]
        self.output_filename = os.path.splitext(self.output_filename)[0]
        # show Qt file directory dialog
        output_path, __ = QtWidgets.QFileDialog.getSaveFileName(
            self,
            self.tr('Output file'),
            '%s_multi_buffer%s' % (
                os.path.join(input_directory, self.output_filename),
                file_extension),
            'GeoJSON (*.geojson);;Shapefile (*.shp)')
        # set selected path to the dialog
        self.output_form.setText(output_path)