@Override
    public int hashCode() {
      return Objects.hash(maxAttempts, waitTimeMs);
    }
Constructor for {@link FixedBackoffPolicy}.
@param maxAttempts The maximum attempts.
@param waitTimeMs The wait time in milliseconds, wait time will not change with time.
ambry-commons/src/main/java/com/github/ambry/commons/RetryPolicies.java