text: import dom_helper
  
  FBEMAIL = '#email'
  FBPASS = '#pass'
  FBLOGIN = 'input[name="login"]'
  FBGRANT = 'input[name="grant_clicked"]'
  
  
  class FacebookDom(dom_helper.DomHelper):
      def is_window_open(self):
          return len(self.driver.window_handles) > 1
  
      def select_window(self):
          self.driver.switch_to_window(self.driver.window_handles[-1])
  
      def reset_window(self):
          self.driver.switch_to_window(self.driver.window_handles[0])
  
      def login(self):
          self.enter_text_field(FBEMAIL, 'nancy_jymsykb_greenberg@tfbnw.net')
          self.enter_text_field(FBPASS, 'LoELw09qtAWwA')
          self.click_button(FBLOGIN)
  
      def do_login_flow(self):
          self.select_window()
          if self.is_window_open():
              self.login()
          self.reset_window()
  
      def do_authorize_flow(self):
          self.select_window()
          if self.is_window_open():
              self.login()
          if self.is_window_open() and self.is_el_present(FBGRANT):
              self.click_button(FBGRANT)
          self.reset_window()