### Question:
PreferencesRecentWorkspacesService implements RecentWorkspacesService { @Override public void clear() { Preferences prefs = Preferences.userRoot().node(WORKSPACES_PATH); cache.clear(); try { prefs.removeNode(); prefs.flush(); } catch (BackingStoreException e) { LOG.error("Unable to clear recently used workspaces", e); } } PreferencesRecentWorkspacesService(); @Override void addWorkspaceLastUsed(File workspace); @Override List<String> getRecentlyUsedWorkspaces(); @Override void clear(); void flush(); @EventListener void onShutdown(ShutdownEvent event);  }### Answer:
@Test public void testClear() throws IOException { victim.addWorkspaceLastUsed(folder.newFile()); victim.flush(); assertEquals(1, victim.getRecentlyUsedWorkspaces().size()); victim.clear(); assertEquals(0, victim.getRecentlyUsedWorkspaces().size()); }