System.Net.Dns.HostResolutionEndHelper C# (CSharp) Method

        private static IPHostEntry HostResolutionEndHelper(IAsyncResult asyncResult)
        {
            //
            // parameter validation
            //
            if (asyncResult == null)
            {
                throw new ArgumentNullException(nameof(asyncResult));
            }
            ResolveAsyncResult castedResult = asyncResult as ResolveAsyncResult;
            if (castedResult == null)
            {
                throw new ArgumentException(SR.net_io_invalidasyncresult, nameof(asyncResult));
            }
            if (castedResult.EndCalled)
            {
                throw new InvalidOperationException(SR.Format(SR.net_io_invalidendcall, nameof(EndResolve)));
            }

            if (NetEventSource.IsEnabled) NetEventSource.Info(null);

            castedResult.InternalWaitForCompletion();
            castedResult.EndCalled = true;

            Exception exception = castedResult.Result as Exception;
            if (exception != null)
            {
                throw exception;
            }

            return (IPHostEntry)castedResult.Result;
        }