scope

# File activerecord/lib/active_record/associations/association_scope.rb, line 10
      def scope(association, connection)
        klass         = association.klass
        reflection    = association.reflection
        scope         = klass.unscoped
        owner         = association.owner
        alias_tracker = AliasTracker.empty connection

        scope.extending! Array(reflection.options[:extend])
        add_constraints(scope, owner, klass, reflection, alias_tracker)
      end