1000:
    cat: App
    1000: None
    1100: Installation and versions
    1500: Preferences

2000:
    cat: Units
    2000: None
    2100:
      cat: Spatial
      2110:
        cat: Sizing
        2115: Stimulus exceeds window size
        2120: Stimulus is sized smaller than a pixel
      2150:
        cat: Positioning
        2155: Position exceeds window dimensions
    2300: Color spaces
    2500: Unsupported

3000:
  cat: Timing
  3100:
    cat: Visual
    3110: Component duration less than 1 screen refresh
    3115: Component start/stop times cannot sync with screen refresh
  3200: Audio
  3400: Response

4000:
  cat: Builder experiments
  4050: Experiment configuration
  4100:
    cat: Timing
    4105: Component start time exceeds stop times
    4115: Frames must be given as whole numbers
  4200:
    cat: Code component syntax
    4205: Python syntax error
    4210: JavaScript syntax error
  4300:
    cat: Components
    4305: Component disabled
    4310: Cannot calculate parameter

5000: Online studies
6000: None
7000: Python dependencies
8000: None
9000: None

9999: Test