multiple tty opened in one screen session

while i was playing with 'console' as serial line i/o, i found nice feature:
'ctrl-a :' and typing 'screen /dev/ttyUSB0 115200' and then 'ctrl-a :' and typing 'screen /dev/ttyACM0 115200' i got 2 serial devices attached.
using 'ctrl-a "' i listed all screens:
###########
Num Name                                                                                                                                                   Flags

  0 ttyUSB0
  1 ttyACM0                                                                                                                                                  
###########

yum 'snippet'

yum reinstall @Some\ Group - yum enters to group mode and reinstall whole group