func (q *DocumentsWriterDeleteQueue) add(term *Term, slice *DeleteSlice) {
	panic("not implemented yet")
}
/* Invariant for document update
package index
import (
	"fmt"
	"sync"
	"sync/atomic"
)
type DocumentsWriterDeleteQueue struct {
	tail                  *Node  
	globalSlice           *DeleteSlice
	globalBufferedUpdates *BufferedUpdates
	globalBufferLock      sync.Locker
	generation int64
}
func newDocumentsWriterDeleteQueue() *DocumentsWriterDeleteQueue {
	return newDocumentsWriterDeleteQueueWithGeneration(0)
}
func newDocumentsWriterDeleteQueueWithGeneration(generation int64) *DocumentsWriterDeleteQueue {
	return newDocumentsWriterDeleteQueueWith(newBufferedUpdates(), generation)
}
func newDocumentsWriterDeleteQueueWith(globalBufferedUpdates *BufferedUpdates, generation int64) *DocumentsWriterDeleteQueue {
	tail := newNode(nil)
	return &DocumentsWriterDeleteQueue{
		globalBufferedUpdates: globalBufferedUpdates,
		globalBufferLock:      &sync.Mutex{},
		generation:            generation,
		tail:        tail,  
		globalSlice: newDeleteSlice(tail),
	}
}