iterate_guarding_exceptions

# File activesupport/lib/active_support/notifications/fanout.rb, line 87
      def iterate_guarding_exceptions(listeners)
        exceptions = nil

        listeners.each do |s|
          yield s
        rescue Exception => e
          exceptions ||= []
          exceptions << e
        end

        if exceptions
          if exceptions.size == 1
            raise exceptions.first
          else
            raise InstrumentationSubscriberError.new(exceptions), cause: exceptions.first
          end
        end

        listeners
      end