public String getJsonString() throws IOException {
    try (OutputStream outputStream = new ByteArrayOutputStream()) {
      new ObjectMapper().writeValue(outputStream, skaffoldFilesTemplate);
      return outputStream.toString();
    }
  }
@Test
  public void testGetJsonString_empty() throws IOException {
    SkaffoldFilesOutput skaffoldFilesOutput = new SkaffoldFilesOutput();
    Assert.assertEquals(
        "{\"build\":[],\"inputs\":[],\"ignore\":[]}", skaffoldFilesOutput.getJsonString());
  }