@Nullable
  public List<File> getClassRoots(@Nullable Project project, @Nullable String rootProjectPath) {
    if (project == null) return null;

    if (rootProjectPath == null) {
      for (Module module : ModuleManager.getInstance(project).getModules()) {
        rootProjectPath = ExternalSystemModulePropertyManager.getInstance(module).getRootProjectPath();
        List<File> result = findGradleSdkClasspath(project, rootProjectPath);
        if (!result.isEmpty()) return result;
      }
    }
    else {
      return findGradleSdkClasspath(project, rootProjectPath);
    }

    return null;
  }
@Nullable
  public List<File> getClassRoots(@Nullable Project project, @Nullable String rootProjectPath)