### Question:
BisqInstaller { public List<FileDescriptor> getSigFileDescriptors(FileDescriptor installerFileDescriptor, List<FileDescriptor> keys) { String suffix = ".asc"; List<FileDescriptor> result = Lists.newArrayList(); for (FileDescriptor key : keys) { if (result.stream().noneMatch(e -> e.getId().equals(key.getId()))) { result.add(FileDescriptor.builder() .type(DownloadType.SIG) .fileName(installerFileDescriptor.getFileName().concat(suffix)) .id(key.getId()) .loadUrl(installerFileDescriptor.getLoadUrl().concat(suffix)) .build()); } else { log.debug("We have already a file with the key: {}", key.getId()); } } return result; }  boolean isSupportedOS(); Optional<DownloadTask> download(String version); VerifyTask verify(List<FileDescriptor> fileDescriptors); static VerifyStatusEnum verifySignature(File pubKeyFile, File sigFile, File dataFile); List<FileDescriptor> getSigFileDescriptors(FileDescriptor installerFileDescriptor, List<FileDescriptor> keys);  }### Answer:
@Test public void getSigFileDescriptors() throws Exception { BisqInstaller bisqInstaller = new BisqInstaller(); FileDescriptor installerFileDescriptor = FileDescriptor.builder().fileName("filename.txt").id("filename").loadUrl("url: FileDescriptor key1 = FileDescriptor.builder().fileName("key1").id("key1").loadUrl("").build(); FileDescriptor key2 = FileDescriptor.builder().fileName("key2").id("key2").loadUrl("").build(); List<FileDescriptor> sigFileDescriptors = bisqInstaller.getSigFileDescriptors(installerFileDescriptor, Lists.newArrayList(key1)); assertEquals(1, sigFileDescriptors.size()); sigFileDescriptors = bisqInstaller.getSigFileDescriptors(installerFileDescriptor, Lists.newArrayList(key1, key2)); assertEquals(2, sigFileDescriptors.size()); log.info("test"); }