title: XStream issue with implicit collections
body: <p>I have the following XML:</p>
  
  <pre><code>&lt;appConfig&gt;
      &lt;database isSource="true" fizz="129"/&gt;
      &lt;database isSource="false" fizz="29494" /&gt;
      &lt;buzz bee="always" /&gt;
  &lt;/appConfig&gt;
  </code></pre>
  
  <p>That should map to the following POJOs:</p>
  
  <pre><code>public class AppConfig {
      private Database sourceDb;
      private Database targetDb;
      private Buzz buzz;
  }
  
  public class Database {
      // Omitted for brevity...
  }
  
  public class Buzz {
      // Omitted for brevity...
  }
  </code></pre>
  
  <p>And have configured the following <code>XStream</code> mapper:</p>
  
  <pre><code>XStream oxMapper = new XStream();
  oxMapper.alias("appConfig", AppConfig.class);
  oxMapper.alias("database", Database.class);
  oxMapper.alias("buzz",  Buzz.class);
  </code></pre>
  
  <p>To read and deserialize the XML like so:</p>
  
  <pre><code>ApplicationConfig appCfg = (ApplicationConfig)oxMapper.fromXML(
          getXMLSnippet());
  </code></pre>
  
  <p>But am getting this error:</p>
  
  <pre><code>Element database of type com.myapp.Database is not defined as field in type com.myapp.AppConfig
  </code></pre>
  
  <p>I read <a href="http://off-topic.biz/en/conversionexception-when-parsing-xml-with-xstream-element-is-not-defined/" rel="nofollow">this article</a> which talks about implicit collections, and <em>believe</em> that XStream thinks my two <code>Database</code> items are a part of a list (implicit collection) when in fact they are not (they should map to 2 different <code>AppConfig</code> properties).</p>
  
  <p>How do I fix this? Thanks in advance!</p>