prompt: Your task is to convert an English description into an ASCII tree format using this style:
  ```
  tests
   +--helpers
   |   `--browser
   +--regression
   |   `--libs
   +--test262
   |   `--test262
   `--unit
       `--fixtures
  ```
  
  Convert this description:
  
  app is a fundamental directory that collects 2 subdirectories: custom-icon and nested.
  In the root directory, 'custom-icon' stores 1 subdirectories: sub.
  Within directory hierarchy 'custom-icon > sub', Inside 'sub', you'll find it is an empty container.
  In the root directory, Inside 'nested', you'll find it is a vacant space.
  
  
  Provide your answer wrapped in <ascii_formatted> tags.
verification_info: {"ground_truth": "app\n +--custom-icon\n |   `--sub\n `--nested", "description": "app is a fundamental directory that collects 2 subdirectories: custom-icon and nested.\nIn the root directory, 'custom-icon' stores 1 subdirectories: sub.\nWithin directory hierarchy 'custom-icon > sub', Inside 'sub', you'll find it is an empty container.\nIn the root directory, Inside 'nested', you'll find it is a vacant space.\n"}