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LightlessSyncAPI/Data/Comparer/GroupDtoComparer.cs

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+using LightlessSync.API.Dto.Group;
+
+namespace LightlessSync.API.Data.Comparer;
+
+public class GroupDtoComparer : IEqualityComparer<GroupDto>
+{
+    private static GroupDtoComparer _instance = new GroupDtoComparer();
+
+    private GroupDtoComparer()
+    { }
+
+    public static GroupDtoComparer Instance => _instance;
+
+    public bool Equals(GroupDto? x, GroupDto? y)
+    {
+        if (x == null || y == null) return false;
+        return x.GID.Equals(y.GID, StringComparison.Ordinal);
+    }
+
+    public int GetHashCode(GroupDto obj)
+    {
+        return obj.Group.GID.GetHashCode();
+    }
+}