Tests retrieving nested directory from the protocol.

Directory: second_level
Nested Directories:
  - Name: third_level_2
  - Name: third_level
Nested Files:
  - Name: second_level_2.txt
    Size: 0
    Type: text/plain
  - Name: second_level.txt
    Size: 0
    Type: text/plain

Directory: test_bucket:second_level
Nested Directories:
  - Name: test_bucket:third_level_2
  - Name: test_bucket:third_level
Nested Files:
  - Name: test_bucket:second_level_2.txt
    Size: 0
    Type: text/plain
  - Name: test_bucket:second_level.txt
    Size: 0
    Type: text/plain