go w.processInterval(ctx, intervalFromEvents(initEvents), 0)
	watchInitializationSignal.Wait()

	// note that we can add three events even though the chanSize is two because
	// one event has been popped off from the input chan
	if !w.add(&watchCacheEvent{Object: makePod(5), ResourceVersion: 5}, time.NewTimer(1*time.Second)) {
		t.Fatal("failed adding an even to the watcher")
	}

	// A dependency on a grey object indicates a cycle which may or may not be
	// valid.
	//
	// When objects turn grey, they are pushed on the object path (a stack);
	// they are popped again when they turn black. Thus, if a grey object (a
	// cycle) is encountered, it is on the object path, and all the objects
	// it depends on are the remaining objects on that path. Color encoding

	p     *printer
	stack []string
}

// trim updates the XML context to match the longest common prefix of the stack
// and the given parents. A closing tag will be written for every parent
// popped. Passing a zero slice or nil will close all the elements.
func (s *parentStack) trim(parents []string) error {
	split := 0
	for ; split < len(parents) && split < len(s.stack); split++ {

	// A dependency on a grey object indicates a cycle which may or may not be
	// valid.
	//
	// When objects turn grey, they are pushed on the object path (a stack);
	// they are popped again when they turn black. Thus, if a grey object (a
	// cycle) is encountered, it is on the object path, and all the objects
	// it depends on are the remaining objects on that path. Color encoding

        // EmptyTensorList -> TensorListPushBack -> TensorListPopBack -> Op
        //                                                  |
        //                                        (Discard popped list)
        //
        // Would have been reduced to "Const -> Op" without this filter.
        // However since we are only allowed to specify the filter at the "Node"

  if (VLOG_IS_ON(1)) {
    for (auto t : op_stack) {
      VLOG(1) << "  " << t;
    }
  }
  while (!op_stack.empty()) {
    const int64_t op = op_stack.back();
    VLOG(1) << "Popped " << op;
    op_stack.pop_back();
    auto op_it = state.op_tape.find(op);
    if (op_it == state.op_tape.end()) {
      // It is possible for ops to end up on the stack if they are unrelated to

		}
	}

	// Ensure there is enough budget for slow processing since
	// the entire watch cache is going to be served through the
	// interval and events won't be popped from the cacheWatcher's
	// input channel until much later.
	cacher.dispatchTimeoutBudget.returnUnused(100 * time.Millisecond)

	// We define a custom index validator such that the interval is

	}
	if len(q.tail) > 0 {
		return q.tail[0]
	}
	return nil
}

// cleanFrontNotWaiting pops any wantConns that are no longer waiting from the head of the
// queue, reporting whether any were popped.
func (q *wantConnQueue) cleanFrontNotWaiting() (cleaned bool) {
	for {
		w := q.peekFront()
		if w == nil || w.waiting() {
			return cleaned
		}
		q.popFront()
		cleaned = true
	}
}

	deferBitsAddr *ssa.Value
	deferBitsTemp *ir.Name

	// line number stack. The current line number is top of stack
	line []src.XPos
	// the last line number processed; it may have been popped
	lastPos src.XPos

	// list of panic calls by function name and line number.
	// Used to deduplicate panic calls.
	panics map[funcLine]*ssa.Block

	cgoUnsafeArgs       bool

  let arguments = (ins
    Arg<TF_ResourceTensor, [{The handle to a stack.}], [TF_StackRead, TF_StackWrite]>:$handle
  );

  let results = (outs
    Res<TF_Tensor, [{The tensor that is popped from the top of the stack.}]>:$elem
  );

  TF_DerivedResultTypeAttr elem_type = TF_DerivedResultTypeAttr<0>;
}

def TF_StackPushV2Op : TF_Op<"StackPushV2", []> {