log

type Logger interface {
	// Debugf uses fmt.Sprintf to log a templated message.
	Debugf(template string, args ...interface{})

	// Infof uses fmt.Sprintf to log a templated message.
	Infof(template string, args ...interface{})

	// Warnf uses fmt.Sprintf to log a templated message.
	Warnf(template string, args ...interface{})

	// Errorf uses fmt.Sprintf to log a templated message.
	Errorf(template string, args ...interface{})

	With(args ...interface{}) Logger

	WithErr(err error) Logger

	Named(name string) Logger
}