code: func newBlockCursor(c *bolt.Cursor, n int) blockCursor { // nolint: unparam
  	cur := blockCursor{
  		cur: c,
  		n:   uint64(n),
  	}
  	cur.buf.key, cur.buf.value = c.First()
  	cur.buf.filled = true
  	return cur
  }
docs: // newBlockCursor returns a new block cursor that wraps cur using n sized blocks.