code: protected Properties getConfigProperties(String packageName) {
      List<String> packageParts = new ArrayList<>(Arrays.asList(packageName.split("\\.")));
      packageParts.add(RobolectricTestRunner.CONFIG_PROPERTIES);
      final String resourceName = Join.join("/", packageParts);
      try (InputStream resourceAsStream = getResourceAsStream(resourceName)) {
        if (resourceAsStream == null) return null;
        Properties properties = new Properties();
        properties.load(resourceAsStream);
        return properties;
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
docs: Return a {@link Properties} file for the given package name, or {@code null} if none is available.
  
  @since 3.2