code: func (pool *ReaderPool) numDeletedDocs(info *SegmentCommitInfo) int {
  	// ensureOpen(false)
  	delCount := info.DelCount()
  	if rld := pool.get(info, false); rld != nil {
  		delCount += rld.pendingDeleteCount()
  	}
  	return delCount
  }
docs: /*
  Obtain the number of deleted docs for a pooled reader. If the reader
  isn't being pooled, the segmentInfo's delCount is returned.
  */