func SetLogger(newLogger logger.Logger) func() {
	origLog := logger.Log
	logger.Log = newLogger
	return func() {
		logger.Log = origLog
	}
}
func SetLogger(newLogger logger.Logger) func() {
	origLog := logger.Log
	logger.Log = newLogger
	return func() {
		logger.Log = origLog
	}
}
// SetLogger installs the given logger as global logger. It returns a function
// that can be used to restore whatever logger was installed beforehand.