This is done for many trains in SWR area. Hence, doesnt come as a surprise.
1) 11139/40: CSMT - GDG Express
2) 12608/09: MAS - MYS Express
3) 11311/12: SUR - HAS Express
4) 16231/32:...
more... MYS-MV Express
5) 16217/18: MYS-SNSI Express... to name a few.