docs: def _run_validators(self, value):
          """Perform validation on ``value``. Raise a :exc:`ValidationError` if
          validation does not succeed.
          """
          if value in self.empty_values:
              return
  
          errors = []
          for validator in self.validators:
              try:
                  validator(value)
              except exceptions.ValidationError as err:
                  if isinstance(err.messages, dict):
                      errors.append(err.messages)
                  else:
                      errors.extend(err.messages)
  
          if errors:
              raise exceptions.ValidationError(errors)