public PipelineConfigs getPartWithPipeline(CaseInsensitiveString pipelineName) {
        for (PipelineConfigs part : parts) {
            if (part.hasPipeline(pipelineName))
                return part;
        }
        return null;
    }
@Test
    public void shouldReturnNullPartWithPipelineNotExists() {
        PipelineConfig pipe1 = PipelineConfigMother.pipelineConfig("pipeline1");
        BasicPipelineConfigs part1 = new BasicPipelineConfigs(pipe1);
        MergePipelineConfigs group = new MergePipelineConfigs(
                part1, new BasicPipelineConfigs());

        assertNull(group.getPartWithPipeline(new CaseInsensitiveString("pipelineX")));

    }