@Override
        protected Map<PluginType, Set<String>> load(PluginSource source) throws IOException {
            return loadManifest(source.location().toUri().toURL());
        }
The class hierarchy is similar to the single-jar because there can only be one manifest per type.
However, the path to that single manifest is accessed via the pluginLocation.
tools/src/main/java/org/apache/kafka/tools/ManifestWorkspace.java