code: def find_tags(self, tag_name, **attribute_filter):
          
          all_tags = [
              self.find_tags_from_xml(
                  i, tag_name, **attribute_filter
              )
              for i in self.xml
          ]
          return [tag for tag_list in all_tags for tag in tag_list]
docs: Return a list of all the matched tags in all available xml
  
          :param str tag: specify the tag name