prompt: Your task is to convert an English description into an ASCII tree format using this style:
  ```
  tests
   +--client_certs
   |   `--password_protected
   +--fixtures
   |   +--session_data
   |   |   +--new
   |   |   `--old
   |   `--xmldata
   |       +--invalid
   |       +--valid
   |       `--xhtml
   `--utils
       `--matching
  ```
  
  Convert this description:
  
  docs is a principal directory that bundles 2 subdirectories: advanced and tutorial.
  In the root directory, 'advanced' has no folders inside.
  At the top level, 'tutorial' has 1 contained folders: security.
  In nested path 'tutorial / security', 'security' has nothing inside.
  
  
  Provide your answer wrapped in <ascii_formatted> tags.
verification_info: {"ground_truth": "docs\n +--advanced\n `--tutorial\n     `--security", "description": "docs is a principal directory that bundles 2 subdirectories: advanced and tutorial.\nIn the root directory, 'advanced' has no folders inside.\nAt the top level, 'tutorial' has 1 contained folders: security.\nIn nested path 'tutorial / security', 'security' has nothing inside.\n"}