never tried jnim until now, but I can see your method `run` is static, but your implementation still as an object argument. As far as I know, only non-static methods have a this argument.
I don't know how you got to the interface you wrote in Nim, but I would create some pipeline that creates a c header from the java class via javah, and then process that c header with c2nim, so that you do not get this type of errors.
