private Properties readPropertiesFile(String fileName) {
    // this file is created by the gradle task :geode-old-versions:createGeodeClasspathsFile
    Properties props = new Properties();
    URL url = VersionManager.class.getResource("/" + fileName);
    if (url == null) {
      loadFailure = "VersionManager: unable to locate " + fileName + " in class-path";
      return props;
    }

    try (InputStream in = url.openStream()) {
      props.load(in);
    } catch (IOException e) {
      loadFailure = "VersionManager: unable to read resource " + fileName;
    }
    return props;
  }
Returns a list of testable versions sorted from oldest to newest

<p>
Note: if you need to compare version strings use {@link TestVersion#compare(String, String)} or
{@link TestVersion#equals}.

@return a list of testable versions sorted from oldest to newest
geode-junit/src/main/java/org/apache/geode/test/version/VersionManager.java