You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: exponential.go
    path of file: ./repos/teller/vendor/github.com/cenkalti/backoff
    
    the code of the file until where you have to start completion: package backoff

import (
	"math/rand"
	"time"
)

/*
ExponentialBackOff is a backoff implementation that increases the backoff
period for each retry attempt using a randomization function that grows exponentially.

NextBackOff()
    
func getRandomValueFromInterval(randomizationFactor, random float64, currentInterval time.Duration) time.Duration {
	var delta = randomizationFactor * float64(currentInterval)
	var minInterval = float64(currentInterval) - delta
	var maxInterval = float64(currentInterval) + delta

	// Get a random value from the range [minInterval, maxInterval].
	// The formula used below has a +1 because if the minInterval is 1 and the maxInterval is 3 then
	// we want a 33% chance for selecting either 1, 2 or 3.
	return time.Duration(minInterval + (random * (maxInterval - minInterval + 1)))
}