@Override
    public ValidationResult validate(RuleBuilderStep step) {
        if (!actions.containsKey(step.function())) {
            return new ValidationResult(true, "Function " + step.function() + " not available as action for rule builder.");
        }

        return new ValidationResult(false, "");
    }
@Test
    void validate() {
        RuleBuilderStep stepWithValidAction = RuleBuilderStep.builder().function(TEST_ACTION).build();
        RuleBuilderStep stepWithInvalidAction = RuleBuilderStep.builder().function("invalidAction").build();

        assertThat(classUnderTest.validate(stepWithValidAction).failed()).isFalse();
        assertThat(classUnderTest.validate(stepWithInvalidAction).failed()).isTrue();
    }