}
        if (FAIL_FAST.equals(failureBehavior)
                || FAIL_AT_END.equals(failureBehavior)
                || FAIL_NEVER.equals(failureBehavior)) {
            this.failureBehavior = failureBehavior;
        } else {
            throw new IllegalArgumentException("Invalid failure behavior (must be one of: '" + FAIL_FAST + "', '"
                    + FAIL_AT_END + "', '" + FAIL_NEVER + "').");
        }
    }