in src/main/scala-2.11+/org/apache/logging/log4j/scala/LoggerMacro.scala [283:287]
def logMarkerCseqThrowable(c: LoggerContext)(level: c.Expr[Level], marker: c.Expr[Marker], message: c.Expr[CharSequence], cause: c.Expr[Throwable]) =
c.universe.reify(
if (c.prefix.splice.delegate.isEnabled(level.splice, marker.splice)) {
c.prefix.splice.logMessage(level.splice, marker.splice, message.splice, cause.splice)
}