docs: def similar_title(post, parameter=None):
  	'''Skip posts with fuzzy-matched (threshold = levenshtein distance / length) title.
  		Parameters (comma-delimited):
  			minimal threshold, at which values are considired similar (float, 0 < x < 1, default: {0});
  			comparison timespan, seconds (int, 0 = inf, default: {1}).'''
  	from feedjack.models import Post
  	threshold, timespan = DEFAULT_SIMILARITY_THRESHOLD, DEFAULT_SIMILARITY_TIMESPAN
  	if parameter:
  		parameter = map(op.methodcaller('strip'), parameter.split(',', 1))
  		threshold = parameter.pop()
  		try: threshold, timespan = parameter.pop(), threshold
  		except IndexError: pass
  		threshold, timespan = float(threshold), int(timespan)
  	similar = Post.objects.filtered(for_display=False)\
  		.exclude(id=post.id).similar(threshold, title=post.title)
  	if timespan:
  		similar = similar.filter(date_updated__gt=timezone.now() - timedelta(seconds=timespan))
  	return not bool(similar.exists())