private URL getManifestUrl() {
        try {
            return filer.getResource(StandardLocation.CLASS_PATH, "", MANIFEST_PATH).toUri().toURL();
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }
Maps annotation data to a plugin configuration node.

@param annotation instance of generator annotation to use to create the build config.
@return ObjectNode to use as plugin configuration node.
smithy-build/src/main/java/software/amazon/smithy/build/processor/SmithyAnnotationProcessor.java