title: StringValues Count shows 1 even when value is null
body: <p>I'm reading a token from <code>QueryString</code> in my ASP.NET Core app and I'm confused about something.</p>
  
  <p>Even when the <code>StringValues</code> has <code>null</code> value, its <code>Count</code> is showing 1 -- see below.</p>
  
  <p><a href="https://i.stack.imgur.com/8GkGz.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8GkGz.jpg" alt="enter image description here"></a></p>
  
  <p>I also tried <code>StringValues.IsNullOrEmpty(token)</code> and that's failing too. How do I reliably check to see if <code>StringValues</code> truly has useful data in it?</p>
  
  <p>UPDATE:
  The code that reads the value is as follows:</p>
  
  <pre><code>if(path.StartsWith("/im") &amp;&amp; context.Request.Query.TryGetValue("access_token", out var token))
  {
     context.Token = token;
  }
  </code></pre>
  
  <p>I'm sending an access_token from my client like so:</p>
  
  <pre><code>const connection = new signalR.HubConnectionBuilder()
      .withUrl("/myhub?AUTHORIZATION=" + _token)
      .configureLogging(signalR.LogLevel.Information)
      .build();
  </code></pre>