code: func MemoryLoader(files map[string]string) Loader {
  	return func(path string) (_ starlark.StringDict, src string, err error) {
  		body, ok := files[path]
  		if !ok {
  			return nil, "", ErrNoModule
  		}
  		return nil, body, nil
  	}
  }
docs: // MemoryLoader returns a loader that loads files from the given map.
  //
  // Useful together with 'assets' package to embed Starlark code into the
  // interpreter binary.