# Output a message with `level` severity without formatting it
	#
	# Only output messages with `level` severity greater than of equal to `self.level`.
	#
	# ~~~
	# var stderr = new StringWriter
	# var logger = new Logger(warn_level, stderr, null)
	#
	# # This message will be displayed:
	# assert logger.add_raw(warn_level, "This is a warning.")
	# assert stderr.to_s.trim.split("\n").last == "This is a warning."
	#
	# # This message will not:
	# assert not logger.add_raw(info_level, "This is some info.")
	# assert stderr.to_s.trim.split("\n").last == "This is a warning."
	# ~~~
	fun add_raw(level: Int, message: Writable): Bool do
		if level < self.level then return false
		out.write(message.write_to_string)
		out.write("\n")
		return true
	end