@Override
    public String toString() {
      return "ExponentialPolicy{" + "maxAttempts=" + maxAttempts + ", initialWaitTimeMs=" + initialWaitTimeMs + '}';
    }
Constructor for {@link ExponentialPolicy}.
@param maxAttempts The maximum attempts.
@param initialWaitTimeMs The initial wait time in milliseconds, wait time will grow exponentially with it.
ambry-commons/src/main/java/com/github/ambry/commons/RetryPolicies.java