Constrain IEntity's TId to IEquatable<TId>

src/Discord.Net/Entities/IEntity.cs

@@ -1,6 +1,9 @@
+using System;
+
 namespace Discord
 {
     public interface IEntity<TId>
+        where TId : IEquatable<TId>
     {
         /// <summary> Gets the unique identifier for this object. </summary>
         TId Id { get; }

src/Discord.Net/Rest/Entities/Entity.cs

@@ -1,8 +1,10 @@
-using Discord.Rest;
+using System;
+using Discord.Rest;
 
 namespace Discord.Rest
 {
     internal abstract class Entity<T> : IEntity<T>
+        where T : IEquatable<T>
     {
         public T Id { get; }