code: @SuppressWarnings("unchecked")
  	<K, E extends PoolableObject<V>> E flagOwner() {
  		this.owner = Thread.currentThread();
  		return (E) this;
  	}
docs: Flags the current thread as the new Owner of this Object
  
  @param <K> the Key wrapped Type
  @param <E> the Entry Type
  @return PoolableObject for method chaining