title: IllegalAddException: No such namespace prefix when adding node with SAX
body: <p>I would like to create a node with a namespace prefix that is not declared but SAX refuses to add it.</p>
  
  <p>The offending row it:</p>
  
  <pre><code>contentItem = content.addElement( "d:" + columnNames[i][0] );
  </code></pre>
  
  <p>I tried to tell SAX that it should not mind:</p>
  
  <pre><code>  SAXReader reader = new SAXReader();
    reader.setFeature( "http://xml.org/sax/features/namespaces", false );
    reader.setFeature( "http://xml.org/sax/features/namespace-prefixes", false );
    reader.setFeature( "http://xml.org/sax/features/validation", false );
  </code></pre>
  
  <p>But this does not help.</p>
  
  <p>I also tried to declare an XMLReader set the feature on that and then assign the XMLReader to the SAXReader. But to no avail. This is the code, just in case:</p>
  
  <pre><code>  SAXReader reader = new SAXReader();
    XMLReader xmlReader = SAXParserFactory.newInstance().newSAXParser().getXMLReader();
    xmlReader.setFeature( "http://xml.org/sax/features/namespaces", false );
    xmlReader.setFeature( "http://xml.org/sax/features/namespace-prefixes", false );
    xmlReader.setFeature( "http://xml.org/sax/features/validation", false );
    reader.setXMLReader( xmlReader );
  </code></pre>
  
  <p>All I want is that SAX stop checking the validity of my XML.</p>
  
  <p>Your help is highly appreciated</p>