prompt: Your task is to convert an English description into an ASCII tree format using this style:
  ```
  test
   +--__snapshots__
   +--fixtures
   |   `--has-vulnerabilities
   `--utils
       `--responses
  ```
  
  Convert this description:
  
  alter_fk is a principal directory that gathers 2 subdirectories: author_app and book_app.
  At the main level, 'author_app' keeps 1 folders: migrations.
  At level 2, in directory path 'author_app / migrations', The 'migrations' repository contains no subdirectories.
  Back to the top level.
  In the root directory, 'book_app' bundles 1 subdirectory elements: migrations.
  In nested path 'book_app > migrations', 'migrations' has yet to be populated.
  Back to the top level.
  
  
  Provide your answer wrapped in <ascii_formatted> tags.
verification_info: {"ground_truth": "alter_fk\n +--author_app\n |   `--migrations\n `--book_app\n     `--migrations", "description": "alter_fk is a principal directory that gathers 2 subdirectories: author_app and book_app.\nAt the main level, 'author_app' keeps 1 folders: migrations.\nAt level 2, in directory path 'author_app / migrations', The 'migrations' repository contains no subdirectories.\nBack to the top level.\nIn the root directory, 'book_app' bundles 1 subdirectory elements: migrations.\nIn nested path 'book_app > migrations', 'migrations' has yet to be populated.\nBack to the top level.\n"}