code: func (s *PublicTransactionPoolAPI) GetTransactionByBlockNumberAndIndex(ctx context.Context, blockNr rpc.BlockNumber, index hexutil.Uint) *RPCTransaction {
  	if block, _ := s.b.BlockByNumber(ctx, blockNr); block != nil {
  		return newRPCTransactionFromBlockIndex(block, uint64(index))
  	}
  	return nil
  }
docs: // GetTransactionByBlockNumberAndIndex returns the transaction for the given block number and index.