: Test for source tree numbering 1: Level A 1: Level B 2: Level B 1: Level C 3: Level B 1: Level C 1: Level D 2: Level A 1: Level B 1: Level C 1: Level D 1: Level E 3: Level A 1: Level B 1: Level C 1: Level D 1: Level E 2: Level D 1: Level E 2: Level C 1: Level D 2: Level B