'Return a string representation of the description.
Useful for error messages.'

def __str__(self):

    return dedent('\n                                                <XBlockFixtureDescriptor:\n                                                                category={0},\n                                                                data={1},\n                                                                metadata={2},\n                                                                grader_type={3},\n                                                                publish={4},\n                                                                children={5},\n                                                                locator={6},\n                                                >\n                                ').strip().format(self.category, self.data, self.metadata, self.grader_type, self.publish, self.children, self.locator)
