How to use the gaiatest.apps.system.regions.activities.Activities function in gaiatest

def tap_share_button(self):
        share_button = Wait(self.marionette).until(
            expected.element_present(*self._share_thumbnail_locator))
        Wait(self.marionette).until(expected.element_displayed(share_button))
        share_button.tap()
        from gaiatest.apps.system.regions.activities import Activities
        return Activities(self.marionette)

def tap_change_wallpaper(self):
        change_wallpaper = Wait(self.marionette).until(
            expected.element_present(*self._change_wallpaper_button_locator))
        Wait(self.marionette).until(expected.element_displayed(change_wallpaper))
        change_wallpaper.tap()

        from gaiatest.apps.system.regions.activities import Activities
        return Activities(self.marionette)

def long_press_context_menu_body(self):
        self.wait_for_condition(lambda m: m.find_element(*self._context_menu_body_locator).is_displayed())
        context_menu_body = self.marionette.find_element(*self._context_menu_body_locator)
        Actions(self.marionette).press(context_menu_body).wait(1).release().perform()

        from gaiatest.apps.system.regions.activities import Activities

        return Activities(self.marionette)

def tap_attachment(self):
        self.marionette.find_element(*self._attach_button_locator).tap()
        from gaiatest.apps.system.regions.activities import Activities
        return Activities(self.marionette)

def tap_share_button(self):
        self.tap_cover_in_player_view()
        self.marionette.find_element(*self._cover_share_locator).tap()
        from gaiatest.apps.system.regions.activities import Activities
        return Activities(self.marionette)

def pick_wallpaper(self):
        self.marionette.find_element(*self._wallpaper_pick_locator).tap()
        return Activities(self.marionette)

def tap_picture(self):
        self.marionette.find_element(*self._thumbnail_photo_locator).tap()
        from gaiatest.apps.system.regions.activities import Activities
        return Activities(self.marionette)