public void walk(Handler handler) {
        walkSubtree(this.rootValidatable, new ConfigSaveValidationContext(null), handler);
    }
@Test
    public void shouldWalkPipelineConfigsInBasicPipelineConfigs() {
        PipelineConfig pipe = mockPipelineConfig();
        BasicPipelineConfigs basicPipelines = new BasicPipelineConfigs(pipe);
        new GoConfigGraphWalker(basicPipelines).walk(Validatable::validate);
        verify(pipe, atLeastOnce()).validate(any(ValidationContext.class));
    }