### Question:
ZkLayoutManager implements LayoutManager { @Override public void deleteLedgerLayout() throws IOException { try { zk.delete(ledgersLayout, -1); } catch (InterruptedException e) { Thread.currentThread().interrupt(); throw new IOException(e); } catch (KeeperException e) { throw new IOException(e); } } ZkLayoutManager(ZooKeeper zk,
                           String ledgersRoot,
                           List<ACL> acls); @VisibleForTesting ZooKeeper getZk(); @Override LedgerLayout readLedgerLayout(); @Override void storeLedgerLayout(LedgerLayout layout); @Override void deleteLedgerLayout();  }### Answer:
@Test public void testDeleteLayout() throws Exception { zkLayoutManager.deleteLedgerLayout(); verify(zk, times(1)) .delete(eq(layoutPath), eq(-1)); }