# File lib/has_many_polymorphs/association.rb, line 70
      def clear(klass = nil)
        load_target
        return if @target.empty?

        if klass
          delete(@target.select {|r| r.is_a? klass })
        else
          @owner.send(@reflection.through_reflection.name).clear
          @target.clear
        end
        []
      end