docs: def is_valid(self, csdl):
          """ Checks if the given CSDL is valid.
  
              Uses API documented at http://dev.datasift.com/docs/api/rest-api/endpoints/validate
  
              :param csdl: CSDL to validate
              :type csdl: str
              :returns: Boolean indicating the validity of the CSDL
              :rtype: bool
              :raises: :class:`~datasift.exceptions.DataSiftApiException`, :class:`requests.exceptions.HTTPError`
          """
          try:
              self.validate(csdl)
          except DataSiftApiException as e:
              if e.response.status_code == 400:
                  return False
              else:
                  raise e
          return True