title: GetRegionsHierarchy failing on documents with barcodes
body: <p>I am using Aspose Words (.Net) and trying to get a region overview of the word document. The problem I am having is that this fails as soon as the document has <code>MERGEBARCODE</code> fields.</p>
  
  <pre><code>var regions = doc.MailMerge.GetRegionsHierarchy();
  </code></pre>
  
  <p>Throws an error: <code>Unable to cast object of type 'Aspose.Words.Fields.FieldMergeBarcode' to type 'Aspose.Words.Fields.FieldMergeField'.</code></p>
  
  <p>Has anybody else come across this, or does anyone know if there is a way to get this to work?</p>