System.Threading.CancellationToken.ThrowIfCancellationRequested C# (CSharp) Method

        public void ThrowIfCancellationRequested()
        {
        }
    }

 public async Task RunAsync(Graph graph, Stream outputStream, RendererLayouts layout, RendererFormats format, CancellationToken cancellationToken)
 {
     cancellationToken.ThrowIfCancellationRequested();
     var fileName = Path.Combine(graphvizBin, GetRendererLayoutExecutable(layout));
     var arguments = GetRendererFormatArgument(format);
     var startInfo = new ProcessStartInfo
     {
         FileName = fileName,
         Arguments = arguments,
         UseShellExecute = false,
         CreateNoWindow = true,
         RedirectStandardInput = true,
         RedirectStandardOutput = true,
         RedirectStandardError = true
     };
     var tcs = new TaskCompletionSource<object>();
     using (var process = Process.Start(startInfo))
     {
         cancellationToken.ThrowIfCancellationRequested();
         cancellationToken.Register(() =>
         {
             tcs.TrySetCanceled();
             process.CloseMainWindow();
         });
         using (var standardInput = process.StandardInput)
         {
             graph.WriteTo(standardInput);
         }
         using (var standardOutput = process.StandardOutput)
         {
             await Task.WhenAny(tcs.Task, standardOutput.BaseStream.CopyToAsync(outputStream, 4096, cancellationToken));
         }
     }
     cancellationToken.ThrowIfCancellationRequested();
 }