default sort of catalog items?

[prjemian]

Is it a feature of databroker to return a list of runs in any specific order (such as chronological)?

When I use a catalog backed by MongoDB (such as BCDA-APS/apstools#498), a for loop over the catalogs comes out that way, so that cat[-1] is the most recent run. When using a catalog backed by Msgpack (such as from databroker-pack or from other older methods such as BCDA-APS/apstools#479), there is no obvious sort order, by any key.