Defined in github.com/aws/aws-sdk-go/service/swf/api.go
If set, specifies the default maximum duration that a task of this activity type can wait before being assigned to a worker. This default can be overridden when scheduling an activity task using the ScheduleActivityTask decision.
The duration is specified in seconds; an integer greater than or equal to 0. The value "NONE" can be used to specify unlimited duration.