Typically CascadingStats objects have an internal state model with timings, the FlowSliceStats is a simplified
Stats object and only reports what the underlying platform reports, not the client side observations.
Implementations may optionally implement the
Provided as an abstract class so that implementations will be resilient to API additions.
- pendingTime - when the slice is created
- startTime - when the slice was told to begin work
- submitTime - when the slice was submitted to a work queue
- runTime - when work began
- finishedTime - when work ended
pending is mostly irrelevant and unavailable, start, submit, and runtime are by default synonymous at the slice level