static <T extends Response> RetryRuleWithContent<T> onException(
            BiPredicate<? super ClientRequestContext, ? super Throwable> exceptionFilter, Backoff backoff) {
        return RetryRuleWithContent.<T>builder().onException(exceptionFilter).thenBackoff(backoff);
    }
Returns a newly created {@link RetryRuleWithContent} that will retry with the specified {@link Backoff}
if an {@link Exception} is raised and the specified {@code exceptionFilter} returns {@code true}.
core/src/main/java/com/linecorp/armeria/client/retry/RetryRuleWithContent.java