code: func (l *txPricedList) Removed() {
  	// Bump the stale counter, but exit if still too low (< 25%)
  	l.stales++
  	if l.stales <= len(*l.items)/4 {
  		return
  	}
  	// Seems we've reached a critical number of stale transactions, reheap
  	reheap := make(priceHeap, 0, l.all.Count())
  
  	l.stales, l.items = 0, &reheap
  	l.all.Range(func(hash common.Hash, tx *types.Transaction) bool {
  		*l.items = append(*l.items, tx)
  		return true
  	})
  	heap.Init(l.items)
  }
docs: // Removed notifies the prices transaction list that an old transaction dropped
  // from the pool. The list will just keep a counter of stale objects and update
  // the heap if a large enough ratio of transactions go stale.