docs: def strip_system_metadata(etree_obj):
      """In-place remove elements and attributes that are only valid in v2 types from v1
      System Metadata.
  
      Args:   etree_obj: ElementTree     ElementTree holding a v1 SystemMetadata.
  
      """
      for series_id_el in etree_obj.findall('seriesId'):
          etree_obj.remove(series_id_el)
      for media_type_el in etree_obj.findall('mediaType'):
          etree_obj.remove(media_type_el)
      for file_name_el in etree_obj.findall('fileName'):
          etree_obj.remove(file_name_el)