@@ -16,12 +16,13 @@
 // 
 
 using Nethermind.Core;
+using Nethermind.TxPool;
 
 namespace Nethermind.Consensus.Transactions
 {
     public class NullTxFilter : ITxFilter
     {
-        public (bool Allowed, string Reason) IsAllowed(Transaction tx, BlockHeader parentHeader) => (true, string.Empty);
+        public (bool Allowed, AddTxResult? Reason) IsAllowed(Transaction tx, BlockHeader parentHeader) => (true, null);
         
         public static readonly NullTxFilter Instance = new(); 
     }
﻿//  Copyright (c) 2021 Demerzel Solutions Limited
//  This file is part of the Nethermind library.
// 
//  The Nethermind library is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
// 
//  The Nethermind library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//  GNU Lesser General Public License for more details.
// 
//  You should have received a copy of the GNU Lesser General Public License
//  along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
// 

using Nethermind.Core;

namespace Nethermind.Consensus.Transactions
{
    public class NullTxFilter : ITxFilter
    {
        public (bool Allowed, string Reason) IsAllowed(Transaction tx, BlockHeader parentHeader) => (true, string.Empty);
        
        public static readonly NullTxFilter Instance = new(); 
    }
}

As we have AddTxResult.Added, we don't need the tuple now, we can simplify this a lot.