Indicates that for this subscription the associated onInvoke callback should be auto-invoked at the specified interval. This provides a pseudo-asynchronous event to trigger (what would normally be) synchronous methods so that they can behave as asynchronous methods.
A typical scenario is a method which must calculate (polled) data over a precise time interval and return the calculated result based on that interval. In this case the method returns data not based on a synchronous call but on a specified time interval.
