UnsupportedOSPlatformAttribute
namespace System.Runtime.Versioning
{
    [AttributeUsage(AttributeTargets.Assembly | AttributeTargets.Module | AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum | AttributeTargets.Constructor | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Interface, AllowMultiple = true, Inherited = false)]
    internal sealed class UnsupportedOSPlatformAttribute : System.Runtime.Versioning.OSPlatformAttribute
    {
        public string Message { get; }
        public UnsupportedOSPlatformAttribute(string platformName)
            : base(platformName)
        {
        }
        public UnsupportedOSPlatformAttribute(string platformName, string message)
            : base(platformName)
        {
            Message = message;
        }
    }
}