log

type Logger interface {
	// Infof is used to print a info level log
	Infof(format string, params ...interface{})
	// Tracef is used to print a trace level log
	Tracef(format string, params ...interface{})
	// Warnf is used to print a warning level log
	Warnf(format string, params ...interface{})
	// Debugf is used to print a debug level log
	Debugf(format string, params ...interface{})
	// Errorf is used to print an error
	Errorf(format string, params ...interface{})

	IsTracing() bool
}

type NullLogger struct{}