change user in pl/sql

Just a quick note about a feature of an internal datapump package (sys.kupp$proc in prvtbpp.plb) that I stumbled upon here, tested on 11gR1:

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
PL/SQL Release 11.1.0.6.0 - Production
CORE    11.1.0.6.0    Production
TNS for Linux: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production

5 Zeilen ausgewählt.

SQL> conn cneu/xxxxxxxxxxx
Connect durchgeführt.

SQL> select user from dual;

USER
------------------------------
CNEU

1 Zeile wurde ausgewählt.

SQL> exec sys.kupp$proc.change_user('SYS')

PL/SQL-Prozedur erfolgreich abgeschlossen.

SQL> select user from dual;

USER
------------------------------
SYS

1 Zeile wurde ausgewählt.

Execute is granted to EXECUTE_CATALOG_ROLE, which is available to DBA,
IMP_FULL_DATABASE, EXP_FULL_DATABASE and SYS. My CNEU user has DBA rights.