title: What's the down side of defining this extension method?
body: <p>I've got a bunch of duplicate code that looks like this:</p>
  
  <pre><code>If mValue is Nothing Return ""
  Return mValue.ToUpper
  </code></pre>
  
  <p>I defined the following extension method to reduce duplicate code:</p>
  
  <pre><code>&lt;System.Runtime.CompilerServices.Extension()&gt;
  Public Function EmptyIfNull(this As String) As String
      If String.IsNullOrEmpty(this) Then Return ""
      Return this
  End Function
  </code></pre>
  
  <p>The duplicate code can be re-written as:</p>
  
  <pre><code>Return mValue.EmptyIfNull.ToUpper
  </code></pre>
  
  <p>Is there a downside to this?</p>