Get the subset definitions (if any) applied to a cohort definition set.
Note that these subset definitions are a copy of those applied to the cohort set.
Modifying these definitions will not modify the base cohort set.
To apply a modification, reapply the subset definition to the cohort definition set data.frame with
addCohortSubsetDefinition with `overwriteExisting = TRUE`.
getSubsetDefinitions(cohortDefinitionSet)list of cohort subset definitions or empty list
A valid cohortDefinitionSet