public SELF onException(BiPredicate<? super ClientRequestContext, ? super Throwable> exceptionFilter) {
        this.exceptionFilter = combinePredicates(this.exceptionFilter, exceptionFilter, "exceptionFilter");
        return self();
    }
Adds the specified {@code exceptionFilter}.

<p>When this is used for a {@link CircuitBreakerRule}, and the specified {@code exceptionFilter} returns
{@code true} for the raised exception, a {@link Response} is reported as a success or failure to a
{@link CircuitBreaker} or ignored depending on the build methods({@code #thenSuccess()},
{@code #thenFailure()} and {@code #thenIgnore()}).
core/src/main/java/com/linecorp/armeria/client/AbstractRuleBuilder.java