### Question:
Medias { public static synchronized String getJarResourcesPrefix() { if (!loader.isPresent()) { throw new LionEngineException(JAR_LOADER_ERROR); } final Media media = Medias.create(Constant.EMPTY_STRING); final String path = media.getFile().getPath().replace(File.separator, Constant.SLASH); final String prefix = loader.get().getPackage().getName().replace(Constant.DOT, Constant.SLASH); final int jarSeparatorIndex = path.indexOf(prefix); return path.substring(jarSeparatorIndex).replace(File.separator, Constant.SLASH); } private  Medias(); static synchronized Media create(String... path); static synchronized void setFactoryMedia(FactoryMedia factoryMedia); static synchronized void setResourcesDirectory(String directory); static synchronized void setLoadFromJar(Class<?> clazz); static synchronized Media get(File file); static synchronized List<Media> getByExtension(String extension, Media folder); static List<Media> getByExtension(File jar, String fullPath, int prefixLength, String extension); static Media getWithSuffix(Media media, String suffix); static synchronized String getResourcesDirectory(); static synchronized Optional<Class<?>> getResourcesLoader(); static synchronized File getJarResources(); static synchronized String getJarResourcesPrefix(); static String getSeparator();  }### Answer:
@Test void testGetJarResourcesPrefix() { Medias.setLoadFromJar(MediasTest.class); final File folder = Medias.create(com.b3dgs.lionengine.Constant.EMPTY_STRING).getFile(); final String prefix = Medias.getResourcesLoader() .get() .getPackage() .getName() .replace(Constant.DOT, Constant.SLASH); final String jarPath = folder.getPath().replace(File.separator, Constant.SLASH); final int jarSeparatorIndex = jarPath.indexOf(prefix); final String resourcesPrefix = Medias.getJarResourcesPrefix(); assertEquals(jarPath.substring(jarSeparatorIndex), resourcesPrefix); }