code: func (s *StanLogger) Debugf(format string, v ...interface{}) {
  	s.executeLogCall(func(log Logger, format string, v ...interface{}) {
  		// This is running under the protection of StanLogging's lock
  		if s.debug {
  			log.Debugf(format, v...)
  		}
  	}, format, v...)
  }
docs: // Debugf logs a debug statement