ONPACKAGE returns a nonvarying character string containing the name of the package where the ASSERT statement that raised the ASSERTION condition is invoked.
>>-ONPACKAGE-+----+-------------------------------------------->< '-()-'
It is in context in an ON-unit for the ASSERTION condition, or for the ERROR or FINISH condition raised as the implicit action for an ASSERTION condition.
If it is used out of context, a null string is returned.
