'Returns json split_test group configurations updated with usage information.'

@staticmethod
def get_split_test_partitions_with_usage(store, course):

    usage_info = GroupConfiguration.get_content_experiment_usage_info(store, course)
    configurations = []
    for partition in get_split_user_partitions(course.user_partitions):
        configuration = partition.to_json()
        configuration['usage'] = usage_info.get(partition.id, [])
        configurations.append(configuration)
    return configurations
