code: func (pool *TxPool) rollbackTxs(hash common.Hash, txc txStateChanges) {
  	batch := pool.chainDb.NewBatch()
  	if list, ok := pool.mined[hash]; ok {
  		for _, tx := range list {
  			txHash := tx.Hash()
  			rawdb.DeleteTxLookupEntry(batch, txHash)
  			pool.pending[txHash] = tx
  			txc.setState(txHash, false)
  		}
  		delete(pool.mined, hash)
  	}
  	batch.Write()
  }
docs: // rollbackTxs marks the transactions contained in recently rolled back blocks
  // as rolled back. It also removes any positional lookup entries.