public void BeginAsyncWait(IntPtr acxh, out IntPtr rpcAsyncHandle)
{
rpcAsyncHandle = NativeMethods.CreateRpcAsyncHandle();
Site.Assert.AreNotEqual<IntPtr>(IntPtr.Zero, rpcAsyncHandle, "Get valid asynchronous handle");
this.pulFlagsOut = Marshal.AllocHGlobal(sizeof(int));
NativeMethods.EcDoAsyncWaitEx(rpcAsyncHandle, acxh, 0, this.pulFlagsOut);
this.VerifyAsyncCallOnRPCTransport();
}