'Helper method to configure a split_test unit with children of type sub_block_category.'

def _setup_split_module(self, sub_block_category):

    self._setup_course_partitions()
    self.split_test = ItemFactory.create(parent=self.unit, category='split_test', display_name=u'split    test    unit', user_partition_id=0)
    sub_block_a = ItemFactory.create(parent=self.split_test, category=sub_block_category, display_name=u'split    test    block    a')
    sub_block_b = ItemFactory.create(parent=self.split_test, category=sub_block_category, display_name=u'split    test    block    b')
    self.split_test.group_id_to_child = {str(index): url for (index, url) in enumerate([sub_block_a.location, sub_block_b.location])}
    self.store.update_item(self.split_test, self.user.id)
    return (sub_block_a, sub_block_b)
