title: XML deserialization: Deserialize missing element into null property value
body: <p>My xml document has a  element that can contains multiple  child elements. In my class, I declare the property as:</p>
  
  <pre><code>[XmlArray("files", IsNullable = true)]
  [XmlArrayItem("file", IsNullable = false)]
  public List&lt;File&gt; Files { get; set; }
  </code></pre>
  
  <p>During deserialization, if the <code>&lt;files&gt;</code> element is missing, I want the Files property to be <strong>null</strong>. However, what happens is that Files is deserialized into an empty List object. How do I prevent that? </p>