diff --git a/rex/rex.go b/rex/rex.go
index 8aa11218..33e74562 100644
--- a/rex/rex.go
+++ b/rex/rex.go
@@ -82,6 +82,7 @@ func (rex *ReprocessingExecutor) AdvanceState(t *state.Task) {
 	}
 }
 
+// GetDS returns a bq Dataset that can be used for rex Table operations.
 func (rex *ReprocessingExecutor) GetDS() (bqext.Dataset, error) {
 	return bqext.NewDataset(rex.Project, rex.Dataset, rex.Options...)
 }