private @Nullable JpsSdkType<?> loadProjectRoot(@Nullable Element root) {
    Pair<String, String> sdkTypeIdAndName = JpsProjectConfigurationLoading.readProjectSdkTypeAndName(root);
    if (sdkTypeIdAndName != null) {
      JpsSdkType<?> sdkType = JpsSdkTableSerializer.getSdkType(sdkTypeIdAndName.first);
      JpsSdkTableSerializer.setSdkReference(myProject.getSdkReferencesTable(), sdkTypeIdAndName.second, sdkType);
      return sdkType;
    }
    return null;
  }
private @Nullable JpsSdkType<?> loadProjectRoot(@Nullable Element root)