not supposed to be passed to the Log method.

ConsoleDebugLogger implements Logger and writes all LevelDebug and above messages to stdout.

ConsoleErrorLogger implements Logger and writes all LevelError log messages to stdout.

ConsoleInfoLogger implements Logger and writes all LevelInfo and above log messages to stdout.

ConsoleTraceLogger implements Logger and writes all log messages to stdout.

ConsoleWarnLogger implements Logger and writes all LevelWarn and above log messages to stdout.

NilLogger drops all log messages.

Logger is minimal logging interface designed to be easily adaptable to any logging library.