code: def add_empty_fields(untl_dict):
      
      # Iterate the ordered UNTL XML element list to determine
      # which elements are missing from the untl_dict.
      for element in UNTL_XML_ORDER:
          if element not in untl_dict:
              # Try to create an element with content and qualifier.
              try:
                  py_object = PYUNTL_DISPATCH[element](
                      content='',
                      qualifier='',
                  )
              except:
                  # Try to create an element with content.
                  try:
                      py_object = PYUNTL_DISPATCH[element](content='')
                  except:
                      # Try to create an element without content.
                      try:
                          py_object = PYUNTL_DISPATCH[element]()
                      except:
                          raise PyuntlException(
                              'Could not add empty element field.'
                          )
                      else:
                          untl_dict[element] = [{'content': {}}]
                  else:
                      # Handle element without children.
                      if not py_object.contained_children:
                          untl_dict[element] = [{'content': ''}]
                      else:
                          untl_dict[element] = [{'content': {}}]
              else:
                  # Handle element without children.
                  if not py_object.contained_children:
                      untl_dict[element] = [{'content': '', 'qualifier': ''}]
                  else:
                      untl_dict[element] = [{'content': {}, 'qualifier': ''}]
              # Add empty contained children.
              for child in py_object.contained_children:
                  untl_dict[element][0].setdefault('content', {})
                  untl_dict[element][0]['content'][child] = ''
      return untl_dict
docs: Add empty values if UNTL fields don't have values.