build

# File activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb, line 24
      def self.build(lhs_class, name, options)
        if options[:join_table]
          KnownTable.new options[:join_table].to_s
        else
          class_name = options.fetch(:class_name) {
            name.to_s.camelize.singularize
          }
          KnownClass.new lhs_class, class_name
        end
      end