oos_util_string.listunagg fires the "ORA-22813: operand value exceeds system limits" exception

[whatsupbros]

Oracle 11g Express Edition

When I try to invoke the oos_util_string.listunagg function (any version of it), it fires the ORA-22813: operand value exceeds system limits exception.

This is because the type oos_util.tab_vc2 is defined as table of varchar2(32767) (and it is used as returning datatype for the pipelined function). But the SQL varchar2 does not support length greater than 4000 (at least in 11g). When I changed the length to 4000, everything worked fine.