public PolicyConfigLoader setExceptionHandler(Handler<Throwable> exceptionHandler) {
        this.exceptionHandler = exceptionHandler;
        return this;
    }
Set the exception handler, invoked if an exception occurs.
@param exceptionHandler the exception handler
@return fluent
gateway/engine/vertx-polling/src/main/java/io/apiman/gateway/engine/vertx/polling/PolicyConfigLoader.java