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

        return new ValidationResult(false, "");
    }
@Test
    void validate() {
        RuleBuilderStep stepWithValidCondition = RuleBuilderStep.builder().function(TEST_CONDITION).build();
        RuleBuilderStep stepWithInValidCondition = RuleBuilderStep.builder().function("INVALID_CONDITION").build();

        assertThat(classUnderTest.validate(stepWithValidCondition).failed()).isFalse();
        assertThat(classUnderTest.validate(stepWithInValidCondition).failed()).isTrue();

    }