options.go
func SampleRate(rate float32) Option {
	return Option(func(c *config) {
		c.Client.Rate = rate
	})
}
func SampleRate(rate float32) Option {
	return Option(func(c *config) {
		c.Client.Rate = rate
	})
}
// SampleRate sets the sample rate of the Client. It allows sending the metrics
// less often which can be useful for performance intensive code paths.