'Creates two courses; one that\'s just a course module, and one that
looks like:
course
chapter
sequential
vertical
/   |    \                                /    |     ---                             /     |        \                         html -> problem -> video -> video2
The side-pointing arrows (->) are PRECEDES relationships; the more
vertical lines are PARENT_OF relationships.'

@classmethod
def setUpClass(cls):

    super(TestDumpToNeo4jCommandBase, cls).setUpClass()
    cls.course = CourseFactory.create()
    cls.chapter = ItemFactory.create(parent=cls.course, category=u'chapter')
    cls.sequential = ItemFactory.create(parent=cls.chapter, category=u'sequential')
    cls.vertical = ItemFactory.create(parent=cls.sequential, category=u'vertical')
    cls.html = ItemFactory.create(parent=cls.vertical, category=u'html')
    cls.problem = ItemFactory.create(parent=cls.vertical, category=u'problem')
    cls.video = ItemFactory.create(parent=cls.vertical, category=u'video')
    cls.video2 = ItemFactory.create(parent=cls.vertical, category=u'video')
    cls.course2 = CourseFactory.create()
    cls.course_strings = [six.text_type(cls.course.id), six.text_type(cls.course2.id)]
