code: func NewEmptySnapshot() *Snapshot {
  	return &Snapshot{
  		Modules: map[string]*SnapshotModule{
  			"": &SnapshotModule{
  				Files: map[string][]byte{},
  			},
  		},
  	}
  }
docs: // NewEmptySnapshot constructs and returns a snapshot containing only an empty
  // root module. This is not useful for anything except placeholders in tests.