protected void destroyEntry(ArrayMapEntryMemory entry) {
        entry.next = null;
        entry.setKey(null);
        entry.setValue(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
jphp-runtime/src/php/runtime/memory/support/ArrayMemoryMap.java