Fix Mempory Pool

Sources/NBitcoin/Utils/DeStreamTxInListExtensions.cs

-using System.Linq;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace NBitcoin
 {
     public static class DeStreamTxInListExtensions
     {
-        public static TxInList RemoveChangePointer(this TxInList txInList)
+        public static IEnumerable<TxIn> RemoveChangePointer(this TxInList txInList)
         {
-            return (TxInList) txInList.Where(p => p.PrevOut.Hash != uint256.Zero);
+            return txInList.Where(p => p.PrevOut.Hash != uint256.Zero);
         }
     }
 }
\ No newline at end of file

Sources/Stratis.Bitcoin.Features.MemoryPool/DeStreamFullNodeBuilderMemoryPoolExtension.cs

@@ -35,7 +35,7 @@ namespace Stratis.Bitcoin.Features.MemoryPool
                         services.AddSingleton<BlockPolicyEstimator>();
                         services.AddSingleton<IMempoolValidator, DeStreamMempoolValidator>();
                         services.AddSingleton<MempoolOrphans>();
-                        services.AddSingleton<DeStreamMempoolManager>();
+                        services.AddSingleton<MempoolManager, DeStreamMempoolManager>();
                         services.AddSingleton<IPooledTransaction, DeStreamMempoolManager>();
                         services.AddSingleton<IPooledGetUnspentTransaction, DeStreamMempoolManager>();
                         services.AddSingleton<MempoolBehavior>();

Sources/Stratis.Bitcoin.Features.MemoryPool/MempoolValidator.cs

@@ -127,7 +127,7 @@ namespace Stratis.Bitcoin.Features.MemoryPool
         private readonly ConcurrentChain chain;
 
         /// <summary>Coin view of the memory pool.</summary>
-        private readonly CoinView coinView;
+        protected readonly CoinView coinView;
 
         /// <inheritdoc cref="IConsensusRules" />
         private readonly IConsensusRules consensusRules;