middle_options

# File activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb, line 71
      def middle_options(join_model)
        middle_options = {}
        middle_options[:class_name] = "#{lhs_model.name}::#{join_model.name}"
        if options.key? :foreign_key
          middle_options[:foreign_key] = options[:foreign_key]
        end
        middle_options
      end