code: def _to_reader_home(self):
      
      # NOTE: Prevents QueryInterface error caused by getting a URL
      # while switched to an iframe
      self.switch_to_default_content()
      self.get(_KindleCloudReaderBrowser._CLOUD_READER_URL)
  
      if self.title == u'Problem loading page':
        raise ConnectionError
  
      # Wait for either the login page or the reader to load
      login_or_reader_loaded = lambda br: (
          br.find_elements_by_id('amzn_kcr') or
          br.find_elements_by_id('KindleLibraryIFrame'))
      self._wait(5).until(login_or_reader_loaded)
  
      try:
        self._wait(5).until(lambda br: br.title == u'Amazon.com Sign In')
      except TimeoutException:
        raise BrowserError('Failed to load Kindle Cloud Reader.')
      else:
        self._login()
docs: Navigate to the Cloud Reader library page.
  
      Raises:
        BrowserError: If the KCR homepage could not be loaded.
        ConnectionError: If there was a connection error.