docs: public final T poll() {
  		if (size > 0) {
  			T result = heap[1]; // save first value
  			heap[1] = heap[size]; // move last to first
  			heap[size] = null; // permit GC of objects
  			size--;
  			downHeap(); // adjust heap
  			return result;
  		} else {
  			return null;
  		}
  	}