src/main/java/org/jivesoftware/smack/util/collections/AbstractHashedMap.java
protected void destroyEntry(HashEntry<K, V> entry) {
        entry.next = null;
        entry.key = null;
        entry.value = null;
    }
protected void destroyEntry(HashEntry<K, V> entry) {
        entry.next = null;
        entry.key = null;
        entry.value = null;
    }
Kills an entry ready for the garbage collector.
<p/>
This implementation prepares the HashEntry for garbage collection.
Subclasses can override this to implement caching (override clear as
well).

@param entry
the entry to destroy