@Override
    public void setBackoffFactor(final double rate) {
        Args.check(rate > 0.0, "Growth rate must be greater than 0.0");
        this.getBackoffFactor().set(rate);
    }
Calculates the new pool size after applying the exponential backoff algorithm.
The new pool size is calculated using the formula: floor(curr / (1 + growthRate) ^ t),
where curr is the current pool size, growthRate is the exponential growth rate, and t is the time interval.

@param curr the current pool size
@return the new pool size after applying the backoff
httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/ExponentialBackoffManager.java