Convert TickDuration to Duration?

[David Nadlinger]

Did I miss a way to convert a TickDuration to a Duration? If there 
really is none, is there a reason for this?

Having to do an immediate conversion to a hnsecs long feels somehow odd:
---
Duration maxFlushInterval;
if (dur!"hnsecs"(flushTimer.peek.hnsecs) > maxFlushInterval) { … }
---

David