code: public boolean getReadAccess(String userId) {
      if (StringUtil.isEmpty(userId)) {
        return false;
      }
      Permissions permissions = permissionsById.get(userId);
      return permissions != null && permissions.getReadPermission();
    }
docs: Get whether the given user id is *explicitly* allowed to read this object. Even if this returns
  {@code false}, the user may still be able to access it if getPublicReadAccess returns
  {@code true} or a role  that the user belongs to has read access.