I tested my udf using pdk. but it was slow because invoking cli repeatedly.
So, I just changed PluginTest to use Driver directly not using invoking cli.
then, I got a following result
test case : Rot13 , Rot12 (just changed class-name of Rot13)
total test count : 4
pdk using cli : 2min 44s
pdk using driver : 1min 49s
I think that we need to improve it's performance in this release to apply many udf.