### Question:
WriterPool extends AbstractPool implements ResourcePool<TableWriter> { public void unlock(CharSequence name) { unlock(name, null); } WriterPool(CairoConfiguration configuration, @Nullable MessageBus messageBus); @Override TableWriter get(CharSequence tableName); boolean lock(CharSequence tableName); int getBusyCount(); int size(); void unlock(CharSequence name); void unlock(CharSequence name, @Nullable TableWriter writer);  }### Answer:
@Test public void testUnlockNonExisting() throws Exception { assertWithPool(pool -> { class X implements PoolListener { short ev = -1; @Override public void onEvent(byte factoryType, long thread, CharSequence name, short event, short segment, short position) { this.ev = event; } } X x = new X(); pool.setPoolListener(x); pool.unlock("x"); Assert.assertEquals(PoolListener.EV_NOT_LOCKED, x.ev); }); }