List<PermissionConfiguration> getExtraDirectoryPermissions() {
    String property = getProperty(PropertyNames.EXTRA_DIRECTORIES_PERMISSIONS);
    if (property != null) {
      return ConfigurationPropertyValidator.parseMapProperty(property).entrySet().stream()
          .map(entry -> new PermissionConfiguration(entry.getKey(), entry.getValue()))
          .collect(Collectors.toList());
    }
    return extraDirectories.permissions;
  }
Gets the configured extra layer file permissions.

@return the configured extra layer file permissions
jib-maven-plugin/src/main/java/com/google/cloud/tools/jib/maven/JibPluginConfiguration.java