def subscribe_to(options = {})
      options = options.merge(source_identifier: @name)
      resp = @client.add_source_identifier_to_subscription(options)
      EventSubscription.new(
        name: resp.data.event_subscription.cust_subscription_id,
        data: resp.data.event_subscription,
        client: @client
      )
    end
def subscribe_to(options = {})
      options = options.merge(source_identifier: @name)
      resp = @client.add_source_identifier_to_subscription(options)
      EventSubscription.new(
        name: resp.data.event_subscription.cust_subscription_id,
        data: resp.data.event_subscription,
        client: @client
      )
    end
@example Request syntax with placeholder values

   eventsubscription = db_security_group.subscribe_to({
     subscription_name: "String", # required
   })
 @param [Hash] options ({})
 @option options [required, String] :subscription_name
   The name of the RDS event notification subscription you want to add a
   source identifier to.
 @return [EventSubscription]