title: how to load ResponseCompressionDefaults function (Blazor WebAssembly SignalR)
body: <p>I am learning Blazor from below Microsoft's tutorial.</p>
  <p>(<a href="https://docs.microsoft.com/ko-kr/aspnet/core/tutorials/signalr-blazor-webassembly?view=aspnetcore-5.0&amp;tabs=visual-studio-mac#prerequisites" rel="nofollow noreferrer">https://docs.microsoft.com/ko-kr/aspnet/core/tutorials/signalr-blazor-webassembly?view=aspnetcore-5.0&amp;tabs=visual-studio-mac#prerequisites</a>)</p>
  <p>When I write  part,
  I want to use &quot;ResponseCompressionDefaults&quot; function, but there is red line below at my editor like screenshot.</p>
  <p>how can I load &quot;ResponseCompressionDefaults&quot; function on my editor?</p>
  <p>Please, help me.</p>
  <p><a href="https://i.stack.imgur.com/OQccQ.png" rel="nofollow noreferrer">enter image description here</a></p>
  <pre><code>public void ConfigureServices(IServiceCollection services)
  {
      services.AddSignalR();
      services.AddControllersWithViews();
      services.AddRazorPages();
      services.AddResponseCompression(opts =&gt;
      {
          opts.MimeTypes = ResponseCompressionDefaults.MimeTypes.Concat(
              new[] { &quot;application/octet-stream&quot; });
      });
  }
  </code></pre>