public static String pluginPathJoined(TestPlugin... plugins) {
        return pluginPath(plugins).stream().map(Path::toString).collect(Collectors.joining(","));
    }
Assemble a plugin path containing some TestPlugin instances
@param plugins One or more plugins which should be included on the plugin path.
@return A list of plugin jar filenames containing the specified test plugins
@throws AssertionError if any plugin failed to load, or no plugins were loaded.
connect/runtime/src/test/java/org/apache/kafka/connect/runtime/isolation/TestPlugins.java