# File lib/aws/record/validator.rb, line 194
      def ensure_exclusive *key_groups
        key_groups.each do |key_group|
          others = key_groups - [key_group]
          Array(key_group).each do |key|
            next unless options.has_key?(key)
            conflicts = others.flatten.select{|other| options.has_key?(other) }
            unless conflicts.empty?
              msg = ":#{key} may not be used with :#{conflicts.first}"
              raise ArgumentError, msg
            end
          end
        end
      end