# File lib/active_record/associations.rb, line 548
      def has_and_belongs_to_many(association_id, options = {})
        validate_options([ :class_name, :table_name, :foreign_key, :association_foreign_key, :conditions,
                           :join_table, :finder_sql, :delete_sql, :insert_sql, :order, :uniq, :before_add, :after_add, 
                           :before_remove, :after_remove ], options.keys)
        association_name, association_class_name, association_class_primary_key_name =
              associate_identification(association_id, options[:class_name], options[:foreign_key])

        require_association_class(association_class_name)

        options[:join_table] ||= join_table_name(undecorated_table_name(self.to_s), undecorated_table_name(association_class_name))

        add_multiple_associated_save_callbacks(association_name)
      
        collection_accessor_methods(association_name, association_class_name, association_class_primary_key_name, options, HasAndBelongsToManyAssociation)

        before_destroy_sql = "DELETE FROM #{options[:join_table]} WHERE #{association_class_primary_key_name} = \\\#{self.quoted_id}"
        module_eval(%{before_destroy "self.connection.delete(%{#{before_destroy_sql}})"}) # "
        add_association_callbacks(association_name, options)
        
        # deprecated api
        deprecated_collection_count_method(association_name)
        deprecated_add_association_relation(association_name)
        deprecated_remove_association_relation(association_name)
        deprecated_has_collection_method(association_name)
      end