title: PdfName.NM in iText TextField not Visible after calling setName()
body: <p>This is how I create a TextField in iText 5.</p>
  
  <pre><code>import com.itextpdf.text.pdf.TextField;
  
  TextField tf = new TextField(stamper.getWriter(), rect, "fieldname");
  tf.setText("fieldvalue");
  tf.setBackgroundColor(BaseColor.WHITE);
  tf.setBorderColor(BaseColor.BLACK);
  tf.getTextField().setName("name_here");
  stamper.addAnnotation(tf.getTextField(), 1);
  </code></pre>
  
  <p>This works. However, when I check in RUPS. PdfName.NM does not exist. setName() is the correct method, right?</p>