public Map<String, Object> attributes() {
    return Optional.ofNullable(attributes).orElse(ImmutableMap.of());
  }
public Map<String, Object> attributes() {
    return Optional.ofNullable(attributes).orElse(ImmutableMap.of());
  }
public Map < String , Object > attributes ( ) { return Optional . ofNullable ( attributes ) . orElse ( ImmutableMap . of ( ) ) ; }
Route attributes, copy of {@link Route.Definition#attributes()}

@return Attributes.
Route attributes copy of { @link Route . Definition#attributes () }