https://github.com/typesafehub/scala-logging
http://eax.me/scala-logging/
http://stackoverflow.com/questions/978252/logging-in-scala
http://biercoff.com/adding-simple-logging-to-scala-project/
https://www.madewithtea.com/cross-version-scala-logging-with-sbt.html

trait Logging {
    protected lazy val log: Log = Log.forClass(getClass)
}
...
trait LazyLog {
  lazy val log = LoggerFactory.getLogger(getClass)

  implicit def logging2Logger(anything: LazyLog): Logger = anything.log
}

class X with LazyLog {
    log.debug("foo")
    debug("bar")
}

https://github.com/typesafehub/scalalogging/blob/master/scalalogging-slf4j/src/main/scala/com/typesafe/scalalogging/slf4j/Logging.scala
    AbstractLogging
        Logging // Lazy
        StrictLogging