code: def process_attrib(element, msg):
          '''process_attrib
  
          High-level api: Delete four attributes from an ElementTree node if they
          exist: operation, insert, value and key. Then a new attribute 'diff' is
          added.
  
          Parameters
          ----------
  
          element : `Element`
              A node needs to be looked at.
  
          msg : `str`
              Message to be added in attribute 'diff'.
  
          Returns
          -------
  
          Element
              Argument 'element' is returned after processing.
          '''
  
          attrib_required = ['type', 'access', 'mandatory']
          for node in element.iter():
              for attrib in node.attrib.keys():
                  if attrib not in attrib_required:
                      del node.attrib[attrib]
              if msg:
                  node.attrib['diff'] = msg
          return elemenf process_attrib(element, msg):
          '''process_attrib
  
          High-level api: Delete four attributes from an ElementTree node if they
          exist: operation, insert, value and key. Then a new attribute 'diff' is
          added.
  
          Parameters
          ----------
  
          element : `Element`
              A node needs to be looked at.
  
          msg : `str`
              Message to be added in attribute 'diff'.
  
          Returns
          -------
  
          Element
              Argument 'element' is returned after processing.
          '''
  
          attrib_required = ['type', 'access', 'mandatory']
          for node in element.iter():
              for attrib in node.attrib.keys():
                  if attrib not in attrib_required:
                      del node.attrib[attrib]
              if msg:
                  node.attrib['diff'] = msg
          return element
docs: process_attrib
  
          High-level api: Delete four attributes from an ElementTree node if they
          exist: operation, insert, value and key. Then a new attribute 'diff' is
          added.
  
          Parameters
          ----------
  
          element : `Element`
              A node needs to be looked at.
  
          msg : `str`
              Message to be added in attribute 'diff'.
  
          Returns
          -------
  
          Element
              Argument 'element' is returned after processing.