public Object pollFirst() { Map.Entry e = map.pollFirstEntry(); return (e != null) ? e.getKey() : null; }
public Object pollFirst() { Map.Entry e = map.pollFirstEntry(); return (e != null) ? e.getKey() : null; }
public Object pollFirst() { Map.Entry e = map.pollFirstEntry(); return (e != null) ? e.getKey() : null; }