### Question:
FileSessionProvider extends SessionProvider { @Override public void delete(String id) throws IOException { assert id != null; LOG.debug("Deleting session: {}", id); SessionMirror session = attach(id, false, true); session.abort(); }  @Override List<String> getCreatedIds(); @Override SessionMirror create(String id); @Override SessionMirror open(String id); @Override void delete(String id); static final String KEY_DIRECTORY; }### Answer:
@Test public void delete() throws Exception { createAndClose("testing"); provider.delete("testing"); List<String> all = new ArrayList<>(provider.getCreatedIds()); assertThat(all.isEmpty(), is(true)); }