namespace System
{
    [TypeForwardedFrom("System.Core, Version=3.5.0.0, Culture=Neutral, PublicKeyToken=b77a5c561934e089")]
    public delegate void Action(T1 arg1, T2 arg2, T3 arg3, T4 arg4);
    {
        public virtual IAsyncResult BeginInvoke(T1 arg1, T2 arg2, T3 arg3, T4 arg4, AsyncCallback callback, object object);
    }
}