Update PolicyContract methods (#806)

src/Neo.Compiler.CSharp/Neo.Compiler.CSharp.csproj

@@ -20,7 +20,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.7.0" />
-    <PackageReference Include="Neo" Version="3.6.0-CI01416" />
+    <PackageReference Include="Neo" Version="3.6.0-CI01421" />
     <PackageReference Include="System.CommandLine" Version="2.0.0-beta4.22272.1" />
     <PackageReference Include="System.CommandLine.NamingConventionBinder" Version="2.0.0-beta4.22272.1" />
   </ItemGroup>

src/Neo.SmartContract.Framework/Native/Policy.cs

@@ -23,5 +23,7 @@ public class Policy
         public static extern uint GetExecFeeFactor();
         public static extern uint GetStoragePrice();
         public static extern bool IsBlocked(UInt160 account);
+        public static extern uint GetAttributeFee(TransactionAttributeType attributeType);
+        public static extern void SetAttributeFee(TransactionAttributeType attributeType, uint value);
     }
 }

src/Neo.SmartContract.Framework/Native/TransactionAttributeType.cs

@@ -0,0 +1,28 @@
+namespace Neo.SmartContract.Framework.Native
+{
+    /// <summary>
+    /// Represents the type of a <see cref="TransactionAttribute"/>.
+    /// </summary>
+    public enum TransactionAttributeType : byte
+    {
+        /// <summary>
+        /// Indicates that the transaction is of high priority.
+        /// </summary>
+        HighPriority = 0x01,
+
+        /// <summary>
+        /// Indicates that the transaction is an oracle response.
+        /// </summary>
+        OracleResponse = 0x11,
+
+        /// <summary>
+        /// Indicates that the transaction is not valid before <see cref="NotValidBefore.Height"/>.
+        /// </summary>
+        NotValidBefore = 0x20,
+
+        /// <summary>
+        /// Indicates that the transaction conflicts with <see cref="Conflicts.Hash"/>.
+        /// </summary>
+        Conflicts = 0x21
+    }
+}