[Core] Adding dummy RecordEntity.cs

Author: Linwenxuan

Lagrange.Core/Message/Entity/RecordEntity.cs

@@ -0,0 +1,21 @@
+using Lagrange.Core.Internal.Packets.Message.Element;
+
+namespace Lagrange.Core.Message.Entity;
+
+public class RecordEntity : IMessageEntity
+{
+    IEnumerable<Elem> IMessageEntity.PackElement()
+    {
+        throw new NotImplementedException();
+    }
+
+    IMessageEntity? IMessageEntity.UnpackElement(Elem elem)
+    {
+        throw new NotImplementedException();
+    }
+
+    public string ToPreviewString()
+    {
+        throw new NotImplementedException();
+    }
+}