- // Source data structure: *Collection, *Group, or
- // nil. Currently populated only for project dirs and
- // top-level collection dirs; *not* populated for
- // /by_id/{uuid} dirs (only subdirs below that). Does not stay
- // up to date with upstream changes.
+ // If not nil, sys() returns the source data structure, which
+ // can be a *Collection, *Group, or nil. Currently populated
+ // only for project dirs and top-level collection dirs. Does
+ // not stay up to date with upstream changes.