Any suggestion on registering the included kernels with Jupyter?

I've looked at `kernel.json`'s and they contain the `$PATH` expression, which is usually reserved for… ehm, `$PATH`, not for the `$CLASSPATH`, which, further, might be set to the path not containing the needed `*.jar`'s. How then the new kernels are being announced to Jupyter? I might be confusing the few things though, feel free to close the issue, my apologies if this is the case then.