PDAcroForm.getFieldIterator() Question

[Barry Neu]

Hello.

The API docs for this method state an iterator is returned which "walks all 
fields in the field tree, in order”.
Is the order left to right, top to bottom on the form .. I was hoping?
I was hoping it was but ehe following code seems to prove otherwise.

PDDocument pdDoc = 
getTemplate("http://localhost:8000/template/Template_MA_ABJ4580MAG5_EF_L70SS_v5.pdf
 <http://localhost:8000/template/Template_MA_ABJ4580MAG5_EF_L70SS_v5.pdf>");
PDAcroForm pdAcroForm = pdDoc.getDocumentCatalog().getAcroForm();
Iterator<PDField> iter = pdAcroForm.getFieldIterator();
while (iter.hasNext()) {
       PDField field = iter.next();
       String fieldName = field.getPartialName();
       System.out.println("field partial name: " + fieldName );
}

PDF in question is here:         https://github.com/BarryNeu/shared 
<https://github.com/BarryNeu/shared>

Thanks in advance.
Barry