anchor.diff:          +cell #[code Path] / #[code None]
           +cell Data path or #[code None].
   
  -+h(2, "set_data_path") set_data_path
  ++h(2, "set_data_path") util.set_data_path
       +tag function
   
   p
  
positive.code:         +cell #[code bool]
          +cell #[code True] if installed package, #[code False] if not.
  
  +h(2, "get_model_package_path") get_model_package_path
      +tag function
  
  p
  
negative.code:         +cell #[code Path]
          +cell Path to model data directory.
  
  +h(2, "is_package") util.is_package
      +tag function
  
  p
  