Fail ip link add name bridge_1 type veth peer

[hazard74]

Hello,
Please help me solve this problem i don't know why it happen :'(
I receive an error after i execute ./bin/trema run ./lib/one_way_bridge.rb -c ./trema.conf
Below is the error

RTNETLINK answers: File exists
/var/lib/gems/2.3.0/gems/phut-0.7.4/lib/phut/shell_runner.rb:5:in sh': sudo ip link add name bridge_1 type veth peer name wlp2s0 failed. (RuntimeError) from /var/lib/gems/2.3.0/gems/phut-0.7.4/lib/phut/virtual_link.rb:81:in add'
from /var/lib/gems/2.3.0/gems/phut-0.7.4/lib/phut/virtual_link.rb:49:in run' from /var/lib/gems/2.3.0/gems/phut-0.7.4/lib/phut/configuration.rb:49:in each'
from /var/lib/gems/2.3.0/gems/phut-0.7.4/lib/phut/configuration.rb:49:in run' from /var/lib/gems/2.3.0/gems/trema-0.8.4/lib/trema/command.rb:110:in block in start_phut'

wlp2s0 is my wireless card network.
also i want to ask, why did it become bridge_1? i write bridge in trema.conf

Please help. ty :)