title: XStream fail on trivial xml
body: <p>I have very simple xml file:</p>
  
  <p><strong>testSimple2.txt</strong></p>
  
  <pre><code>&lt;root&gt;
    &lt;document&gt;
    &lt;/document&gt;
  &lt;/root&gt;
  </code></pre>
  
  <p>But for some reason I can't deserialize it with XStream.</p>
  
  <p><strong>Root.java</strong></p>
  
  <pre><code>@XStreamAlias("root")
  public class Root {
  
   @XStreamAlias("document")
   static public class Document {
   }
   @XStreamAlias("document")
   Document document;
  
  }
  </code></pre>
  
  <p><strong>Main.java</strong></p>
  
  <p>Main code:</p>
  
  <pre><code>XStream xstream = new XStream();
  xstream.autodetectAnnotations(true);
  xstream.processAnnotations(Root.class);
  Root newJoe = (Root) xstream.fromXML(new File("testSimple2.txt"), Root.class); //Exception here
  </code></pre>
  
  <p>The following exception is thrown.</p>
  
  <pre><code>com.thoughtworks.xstream.converters.ConversionException: Element document of type verySimple.Root$Document is not defined as field in type java.lang.Class
  ---- Debugging information ----
  class               : verySimple.Root
  required-type       : verySimple.Root
  converter-type      : com.thoughtworks.xstream.converters.reflection.ReflectionConverter
  path                : /root/document
  line number         : 3
  version             : null
  -------------------------------
      at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.writeValueToImplicitCollection(AbstractReflectionConverter.java:403)
      at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:334)
      at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:234)
      at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
      at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
      at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
      at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
      at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
      at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
      at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1058)
      at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1042)
      at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1006)
      at verySimple.RootProcess.main(RootProcess.java:26)
  </code></pre>
  
  <p>I know there must be some simple mistake, but I can't see it. Please, help.</p>