Fix [SonarQube] Avoid commented-out lines of code (A block of
commented-out lines of code should be removed)

Add whitespace for readability
Fix [SonarQube] Generic exceptions Error, RuntimeException, Throwable
and Exception should never be thrown (Define and throw a dedicated
exception instead of using a generic one)
Add logger
Expand wildcard import org.dmilne.weka.wrapper.* to declare individual
classes
Fix [SonarQube] Generic exceptions Error, RuntimeException, Throwable
and Exception should never be thrown (Define and throw a dedicated
exception instead of using a generic one)