invert

# File activerecord/lib/active_record/relation/where_clause.rb, line 85
      def invert
        if predicates.size == 1
          inverted_predicates = [ invert_predicate(predicates.first) ]
        else
          inverted_predicates = [ Arel::Nodes::Not.new(ast) ]
        end

        WhereClause.new(inverted_predicates)
      end