'the children of retrieved courses should be the same with course and ccx keys'

def test_get_children(self):

    course_key = self.ccx_locator.to_course_locator()
    course = self.get_course(course_key)
    ccx = self.get_course(self.ccx_locator)
    test_fodder = izip_longest(self.get_all_children_bf(course), self.get_all_children_bf(ccx))
    for (expected, actual) in test_fodder:
        if (expected is None):
            self.fail('course    children    exhausted    before    ccx    children')
        if (actual is None):
            self.fail('ccx    children    exhausted    before    course    children')
        self.assertEqual(expected.display_name, actual.display_name)
        self.assertEqual(expected.location.course_key, course_key)
        self.assertEqual(actual.location.course_key, self.ccx_locator)
