docs: public T get( E key )
      {
          Entry<E, T> entry = null;
          synchronized(this) {
              entry = map.get(key);
              if (map.get(key) == null)
                  return null;
          
              entry.prev.next = entry.next;
              entry.next.prev = entry.prev;
              
              entry.prev = this.head;
              entry.next = this.head.next;
              this.head.next.prev = entry;
              this.head.next = entry;
          }
          
          return entry.value;
      }