code: func (logger *Logger) SetOutput(out io.Writer) {
  	unsafeStd := (*unsafe.Pointer)(unsafe.Pointer(&logger.std))
  	old := logger.std
  	logger.std.Out = out
  	atomic.CompareAndSwapPointer(unsafeStd, unsafe.Pointer(old), unsafe.Pointer(logger.std))
  
  }
docs: // SetOutput sets the standard logger output.