:return: The resource (as json), or None

def filter_resource(self, resource_name, field_name, field_value,
                        result_handler=ONE_RESULT):
        """
        :return: The resource (as json), or None
        """
        return self.multi_filter_resource(resource_name,
                                          {field_name: field_value},
                                          result_handler=result_handler)