def add_subscriber(options = {})
      options = options.merge(subscription_name: @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 add_subscriber(options = {})
      options = options.merge(subscription_name: @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
@!group Actions
 @example Request syntax with placeholder values

   eventsubscription = event_subscription.add_subscriber({
     source_identifier: "String", # required
   })
 @param [Hash] options ({})
 @option options [required, String] :source_identifier
   The identifier of the event source to be added.

   Constraints:

   * If the source type is a DB instance, then a `DBInstanceIdentifier`
     must be supplied.

   * If the source type is a DB security group, a `DBSecurityGroupName`
     must be supplied.

   * If the source type is a DB parameter group, a `DBParameterGroupName`
     must be supplied.

   * If the source type is a DB snapshot, a `DBSnapshotIdentifier` must
     be supplied.
 @return [EventSubscription]