@SuppressWarnings("unchecked")
  private void updateCache(ListMultimap<String, ? extends Permission> newPermissions,
    PermissionCache cacheToUpdate) {
    for (String name : newPermissions.keySet()) {
      for (Permission permission : newPermissions.get(name)) {
        cacheToUpdate.put(name, permission);
      }
    }
  }
Updates the internal namespace permissions cache for specified namespace.
@param namespace updated namespace
@param nsPerms   new namespace permissions
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AuthManager.java