warn

abstract fun warn(msg: () -> Any?)

abstract fun warn(marker: Marker?, msg: () -> Any?)

Lazy add a log message if isWarnEnabled is true

abstract fun warn(t: Throwable?, msg: () -> Any?)

abstract fun warn(marker: Marker?, t: Throwable?, msg: () -> Any?)

Lazy add a log message with throwable payload if isWarnEnabled is true