Fix [SonarQube] Execution of the Garbage Collector should be triggered
only by the JVM (Don't try to be smarter than the JVM, remove this call
to run the garbage collector)
Replace calls to System#out with #logger.info
Fix [SonarQube] Useless Operation On Immutable (An operation on an
Immutable object (String, BigDecimal or BigInteger) won't change the
object itself)
Add javadoc