private @Nullable Image getImage(@NotNull URL url) {
    Image inMemory = myImageResolver.resolveImage(url.toExternalForm());
    if (inMemory != null) {
      return inMemory;
    }
    return Toolkit.getDefaultToolkit().createImage(
      new RenderableImageProducer(
        new DocumentationRenderableImage(
          Objects.requireNonNullElse(builtinServerUrl(url), url),
          myReferenceComponent
        ),
        null
      )
    );
  }
private @Nullable Image getImage(@NotNull URL url)