objects extending app are not executed in the REPL

[jvr-ks]

Objects extending app are not executed in the REPL

example: in variances.ipynb

object CovarianceTest extends App { ...

-> defined object CovarianceTest

but nothing happens!

but adding: CovarianceTest.main(Array.empty)

-> Whiskers Tom Fido Rex

defined object CovarianceTest