docs: def _read_tags_for_revset(self, spec):
  		"""
  		Return TaggedRevision for each tag/rev combination in the revset spec
  		"""
  		cmd = [
  			'log', '--style', 'default', '--config', 'defaults.log=',
  			'-r', spec]
  		res = self._invoke(*cmd)
  		header_pattern = re.compile(r'(?P<header>\w+?):\s+(?P<value>.*)')
  		match_res = map(header_pattern.match, res.splitlines())
  		matched_lines = filter(None, match_res)
  		matches = (match.groupdict() for match in matched_lines)
  		for match in matches:
  			if match['header'] == 'changeset':
  				id, sep, rev = match['value'].partition(':')
  			if match['header'] == 'tag':
  				tag = match['value']
  				yield TaggedRevision(tag, rev)