code: def list_unique(cls):
  		'''Return all unique namespaces
  
  		:returns: a list of all predicates 
  		:rtype: list of ckan.model.semantictag.Predicate objects
  
  		'''
  		query = meta.Session.query(Predicate).distinct(Predicate.namespace)
  		return query.all(f list_unique(cls):
  		'''Return all unique namespaces
  
  		:returns: a list of all predicates 
  		:rtype: list of ckan.model.semantictag.Predicate objects
  
  		'''
  		query = meta.Session.query(Predicate).distinct(Predicate.namespace)
  		return query.all()
docs: Return all unique namespaces
  
  		:returns: a list of all predicates 
  		:rtype: list of ckan.model.semantictag.Predicate objects