private InputStream getRetryLibraryStream() {
    // TODO: read from extensions-specific libraries here
    return ConfigUtils.getCombinedInputStream(ImmutableList.of(RETRY_LIBRARY_PATH));
  }
{@link SettingsExtension} that reads configuration from YAML files on the classpath.
extensions/config/portability-config-yaml/src/main/java/org/datatransferproject/config/yaml/YamlSettingsExtension.java