AsyncOperationManager.cs

using System.Security.Permissions;
using System.Threading;

namespace System.ComponentModel
{
    [global::__DynamicallyInvokable]
    [HostProtection(SecurityAction.LinkDemand, SharedState = true)]
    public static class AsyncOperationManager
    {
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        [global::__DynamicallyInvokable]
        public static SynchronizationContext SynchronizationContext
        {
            [global::__DynamicallyInvokable]
            get
            {
                if (SynchronizationContext.Current == null)
                {
                    SynchronizationContext.SetSynchronizationContext(new SynchronizationContext());
                }
                return SynchronizationContext.Current;
            }
            [global::__DynamicallyInvokable]
            [PermissionSet(SecurityAction.LinkDemand, Name = "FullTrust")]
            set
            {
                SynchronizationContext.SetSynchronizationContext(value);
            }
        }

        [global::__DynamicallyInvokable]
        public static AsyncOperation CreateOperation(object userSuppliedState)
        {
            return AsyncOperation.CreateOperation(userSuppliedState, SynchronizationContext);
        }
    }
}