code: def get_error_messages(self):
          
          try:
              error_elms = self.get_elms(class_name='error')
          except NoSuchElementException:
              return []
          else:
              try:
                  error_values = [error_elm.get_attribute('error') for error_elm in error_elms]
              except Exception:
                  error_values = [error_elm.text for error_elm in error_elms]
              finally:
                  return error_values
docs: Method returning error messages. Should return list of messages.
  
          By default it find element with class ``error`` and theirs value in
          attribute ``error`` or text if that attribute is missing. You can change
          this method accordingly to your app.
  
          Error messages returned from this method are used in decorators
          :py:func:`.expected_error_messages` and :py:func:`.allowed_error_messages`.