### Question:
InMemorySlug implements Slug { @Override public synchronized String nextPath() { long id=this.version++; String result = this.preferredPath; if(id>0) { result+="_"+id; } return result; } private  InMemorySlug(ResourceId containerId, String preferredPath, long version); @Override ResourceId containerId(); @Override String preferredPath(); @Override synchronized long version(); @Override synchronized String nextPath(); @Override String toString();  }### Answer:
@Test public void testNextPath$default() throws Exception { InMemorySlug slug=InMemorySlug.create("slug", container); assertThat(slug.nextPath(),equalTo("slug")); }