code: func (l *Loader) ImportSourcesFromSnapshot(snap *Snapshot) {
  	p := l.Parser()
  	for _, m := range snap.Modules {
  		baseDir := m.Dir
  		for fn, src := range m.Files {
  			fullPath := filepath.Join(baseDir, fn)
  			p.ForceFileSource(fullPath, src)
  		}
  	}
  }
docs: // ImportSourcesFromSnapshot writes into the receiver's source code the
  // source files from the given snapshot.
  //
  // This is similar to ImportSources but knows how to unpack and flatten a
  // snapshot data structure to get the corresponding flat source file map.