// and acts as a store barrier for writing the slot.
	d.headTail.Add(1 << dequeueBits)
	return true
}

// popHead removes and returns the element at the head of the queue.
// It returns false if the queue is empty. It must only be called by a
// single producer.
func (d *poolDequeue) popHead() (any, bool) {
	var slot *eface
	for {
		ptrs := d.headTail.Load()
		head, tail := d.unpack(ptrs)
		if tail == head {

		}
	}
	// Check that at least some PopHeads succeeded. We skip this
	// check in short mode because it's common enough that the
	// queue will stay nearly empty all the time and a PopTail
	// will happen during the window between every PushHead and
	// PopHead.
	if !testing.Short() && nPopHead == 0 {
		t.Errorf("popHead never succeeded")
	}
}

func TestNilPool(t *testing.T) {

	New func() any
}

// Local per-P Pool appendix.
type poolLocalInternal struct {
	private any       // Can be used only by the respective P.
	shared  poolChain // Local P can pushHead/popHead; any P can popTail.
}

type poolLocal struct {
	poolLocalInternal

	// Prevents false sharing on widespread platforms with
	// 128 mod (cache line size) = 0 .

		if block != nil {
			// Check the popped value.
			if block.popped.Load() == 0 {
				// popped should never be zero because that means we have
				// pushed at least one value but not yet popped if this
				// block pointer is not nil.
				throw("span set block with unpopped elements found in reset")
			}
			if block.popped.Load() == spanSetBlockEntries {
				// popped should also never be equal to spanSetBlockEntries

                                test("throwsExceptionWhenPopped()") {
                                    operationDisplayName "throws EmptyStackException when popped"
                                    testDisplayName "throws EmptyStackException when popped"
                                }
                                testClass("org.example.TestingAStackDemo\$WhenNew\$AfterPushing") {

        }

        public List<FileSystemLocationSnapshot> pop() {
            List<FileSystemLocationSnapshot> popped = stack.pollLast();
            if (popped == null) {
                throw new IllegalStateException("Stack empty");
            }
            return popped;
        }
    }

    private static String toAbsolutePath(Collection<String> parents, String fileName) {

// source can change over time - i.e. for watchCache circular
// buffer. When the circular buffer is full and an event needs
// to be popped off, watchCache::startIndex is incremented. In
// this case, an interval tracking that popped event is valid
// only if it has already been copied to its internal buffer.
// However, for efficiency we perform that lazily and we mark

	// Simulate a pod being popped by the scheduler,
	// At this time, unschedulable pod should be popped.
	p1, err := q.Pop(logger)
	if err != nil {
		t.Errorf("Error while popping the head of the queue: %v", err)
	}
	if p1.Pod != unschedulablePod {
		t.Errorf("Expected that test-pod-unscheduled was popped, got %v", p1.Pod.Name)
	}

	s.pop(n.Pos())
	*s = append((*s), n)
}

// pop pops all nodes that appear lexically before pos
// (i.e., whose lexical extent has ended before or at pos).
// It returns the last node popped.
func (s *nodeStack) pop(pos token.Pos) (top Node) {
	i := len(*s)
	for i > 0 && (*s)[i-1].End() <= pos {
		top = (*s)[i-1]
		i--
	}
	*s = (*s)[0:i]
	return top
}

	// are popped from this heap before the scheduler looks at activeQ
	podBackoffQ *heap.Heap
	// unschedulablePods holds pods that have been tried and determined unschedulable.
	unschedulablePods *UnschedulablePods
	// schedulingCycle represents sequence number of scheduling cycle and is incremented
	// when a pod is popped.
	schedulingCycle int64