docs: def str_is_well_formed(xml_str):
      """
    Args:
      xml_str : str
        DataONE API XML doc.
  
    Returns:
      bool: **True** if XML doc is well formed.
    """
      try:
          str_to_etree(xml_str)
      except xml.etree.ElementTree.ParseError:
          return False
      else:
          return True