title: What is the Syntax error StyleCop is complaining about?
body: <p>Working with code from Jon Skeet's <a href="http://jonskeet.uk/csharp/miscutil/" rel="nofollow noreferrer">MiscUtil library</a>, I came across this constructor:</p>
  
  <pre><code>public SmartEnumerable(IEnumerable&lt;T&gt; enumerable)
  {
      if (enumerable == null)
      {
          throw new ArgumentNullException ("enumerable");
      }
  
      this.enumerable = enumerable;
  }
  </code></pre>
  
  <p>I have both ReSharper and the StyleCop extension installed. I was curious to see what the R# suggestion here would be. It was simplifying the code to the following:</p>
  
  <pre><code>public SmartEnumerable(IEnumerable&lt;T&gt; enumerable)
  {
      this.enumerable = enumerable ?? throw new ArgumentNullException(nameof(enumerable));
  }
  </code></pre>
  
  <p>StyleCop however has immediately complained with an error message:</p>
  
  <blockquote>
    <p>A syntax error has been discovered in file SmartEnumerable.cs [StyleCop Rule: SA0102]</p>
  </blockquote>
  
  <p>I am working on a .NET Standard 1.6 project with VS2017.</p>
  
  <p><a href="https://i.stack.imgur.com/UAKrD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UAKrD.png" alt="enter image description here"></a></p>