@Override
    public boolean isEmpty() {
        checkState(!destroyed, destroyedMessage);
        return size() == 0;
    }
@Test
    public void testIsEmpty() throws Exception {
        expectPeerMessage(clusterCommunicator);

        assertTrue(ecMap.isEmpty());
        ecMap.put(KEY1, VALUE1);
        assertFalse(ecMap.isEmpty());
        ecMap.remove(KEY1);
        assertTrue(ecMap.isEmpty());
    }