'Returns all units names and their urls.
Returns:
{\'group_id\':
\'label\': \'Unit 1 / Problem 1\',
\'url\': \'url_to_unit_1\'
\'label\': \'Unit 2 / Problem 2\',
\'url\': \'url_to_unit_2\''

@staticmethod
def get_partitions_usage_info(store, course):

    items = store.get_items(course.id, settings={'group_access': {'$exists': True}}, include_orphans=False)
    usage_info = {}
    for (item, group_id) in GroupConfiguration._iterate_items_and_group_ids(course, items):
        if (group_id not in usage_info):
            usage_info[group_id] = []
        unit = item.get_parent()
        if (not unit):
            log.warning('Unable    to    find    parent    for    component    %s', item.location)
            continue
        usage_info = GroupConfiguration._get_usage_info(course, unit=unit, item=item, usage_info=usage_info, group_id=group_id)
    return usage_info
