How to use the qtpy.QtCore.Slot function in QtPy

    @QtCore.Slot()
    def set_tilt_point3(self):
        """Gets the third reference point for tilt correction."""
        self.point3 = np.array(self._scanning_device.get_scanner_position()[:3])
        self.signal_tilt_correction_update.emit()

    @QtCore.Slot(str)
    def set_alternative_data_type(self, alt_data_type):
        """

        @param alt_data_type:
        @return:
        """
        if isinstance(alt_data_type, str):
            self.sigAlternativeDataTypeChanged.emit(alt_data_type)
        return

    @Slot(str, int, str, object)
    def load(self, filenames=None, goto=None, word='',
             editorwindow=None, processevents=True, start_column=None,
             set_focus=True, add_where='end'):
        """
        Load a text file
        editorwindow: load in this editorwindow (useful when clicking on
        outline explorer with multiple editor windows)
        processevents: determines if processEvents() should be called at the
        end of this method (set to False to prevent keyboard events from
        creeping through to the editor during debugging)
        """
        # Switch to editor before trying to load a file
        try:
            self.switch_to_plugin()
        except AttributeError:
            pass

    @Slot(object)
    def show_syspath(self, syspath):
        """Show sys.path contents."""
        if syspath is not None:
            editor = CollectionsEditor(self)
            editor.setup(syspath, title="sys.path contents", readonly=True,
                         width=600, icon=ima.icon('syspath'))
            self.dialog_manager.show(editor)
        else:
            return

    @QtCore.Slot()
    def _z_slider_released(self):
        pos_dict = {'z': self._mw.z_slider.value()}
        self._update_target_display(pos_dict, exclude_widget=self._mw.z_slider)
        self.move_scanner_position(pos_dict)
        return

    @QtCore.Slot(int)
    def set_number_of_plots(self, plt_count):
        with self.threadlock:
            if not isinstance(plt_count, int):
                raise TypeError
            if plt_count < 1:
                self.log.error('number of plots must be integer >= 1.')
                return
            while self.number_of_plots < plt_count:
                self.add_plot()
            while self.number_of_plots > plt_count:
                self.remove_plot()

    @Slot()
    def toggle_buttons(self):
        """Toggle + and - buttons."""
        if len(self.table.selectedItems()) == 2:  # one row (2 items) selected
            self.add_button.setEnabled(True)
            self.remove_button.setEnabled(True)
        elif len(self.table.selectedItems()) > 2:  # more than one row selected
            self.add_button.setEnabled(False)
            self.remove_button.setEnabled(True)
        else:  # no rows selected
            self.add_button.setEnabled(False)
            self.remove_button.setEnabled(False)

    @Slot(int)
    @Slot(object)
    def setCurrentLine(self, line):
        cursor = QTextCursor(self.document().findBlockByLineNumber(line - 1))
        self.setTextCursor(cursor)
        self.centerCursor()

    @Slot(bool, object)
    def _finish_command(self, executed, result):
        if result is not None:
            self._insert_output_text(
                repr(result),
                prompt=self._ps_out % self._current_line)
            self._insert_output_text('\n')

        if executed and self._last_input:
            self._current_line += 1
        self._more = False
        self._show_cursor()
        self._update_ps(self._more)
        self._show_ps()

    @Slot(bool)
    @Slot(list)
    def import_data(self, filenames=None):
        """Import data from text file."""
        title = _("Import data")
        if filenames is None:
            if self.filename is None:
                basedir = getcwd()
            else:
                basedir = osp.dirname(self.filename)
            filenames, _selfilter = getopenfilenames(self, title, basedir,
                                                     iofunctions.load_filters)
            if not filenames:
                return
        elif is_text_string(filenames):
            filenames = [filenames]