  @Test
  public void shouldTransformToBpmnXmlString() throws IOException {

    // given:
    BpmnModelExporter bpmnModelExporter = new BpmnModelExporter();
    FlowBuilder emptyFlow = new BpmnFlowBuilder() {
      @Override
      public void define() {}

      @Override
      public String getId() {
        return "emptyFlow";
      }
    };
    // when:
    String bpmnXml = bpmnModelExporter.toBpmnXml(emptyFlow);
    // then:
    assertThat(bpmnXml).isEqualTo(emptyFlowContent());
  }