Debug will print when logger's Level is debug.

Debugf will print when logger's Level is debug.

Error will print only when logger's Level is error, warn, info or debug.

Errorf will print only when logger's Level is error, warn, info or debug.

Fatal `os.Exit(1)` exit no matter the level of the logger.

Fatalf will `os.Exit(1)` no matter the level of the logger.

Info will print when logger's Level is info or debug.

Infof will print when logger's Level is info or debug.

Print prints a log message without levels and colors.

Printf prints a log message without levels and colors.

Warn will print when logger's Level is warn, info or debug.

Warnf will print when logger's Level is warn, info or debug.