code: def _style_name(self, el):
          
          if el.attributes is None:
              return None
          style_field = ('urn:oasis:names:tc:opendocument:xmlns:text:1.0',
                         'style-name')
          name = el.attributes.get(style_field, None)
          if not name:
              return None
          return self._get_style_name(name)
docs: Return the style name of an element.