apewer-dotnet/Apewer.Windows/Externals/System/Runtime/CompilerServices/ExtensionAttribute.cs

#if NET20

namespace System.Runtime.CompilerServices
{

    /// <summary></summary>
    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Class | AttributeTargets.Assembly)]
    public sealed class ExtensionAttribute : Attribute
    {
    }

}

#endif