### Question:
NoopId implements Id { @Override public String toString() { return name(); } private  NoopId(); @Override String name(); @Override Iterable<Tag> tags(); @Override Id withTag(String k, String v); @Override Id withTag(Tag tag); @Override Id withTags(Iterable<Tag> tags); @Override Id withTags(Map<String, String> tags); @Override String toString(); @Override String getKey(int i); @Override String getValue(int i); @Override int size();  }### Answer:
@Test public void testToString() { Assertions.assertEquals(NoopId.INSTANCE.toString(), "noop"); }