if no TTL value is set on the message itself. Provided in the [TimeSpan](#timespan-format)
format.
*`lock_duration` - (Optional) The lock duration for the subscription, maximum
supported value is 5 minutes. Defaults to 1 minute.
*`dead_lettering_on_filter_evaluation_exceptions` - (Optional) Boolean flag which
controls whether the Subscription has dead letter support on Filter evaluation
exceptions. Defaults to false.
*`dead_lettering_on_message_expiration` - (Optional) Boolean flag which controls
whether the Subscription has dead letter support when a message expires. Defaults
to false.
*`enable_batched_operations` - (Optional) Boolean flag which controls whether the
Subscription supports batched operations. Defaults to false.
*`requires_session` - (Optional) Boolean flag which controls whether this Subscription
supports the concept of a session. Defaults to false. Changing this forces a
new resource to be created.
### TimeSpan Format
Some arguments for this resource are required in the TimeSpan format which is
used to represent a lengh of time. The supported format is documented [here](https://msdn.microsoft.com/en-us/library/se73z7b9(v=vs.110).aspx#Anchor_2)