for (int i = 0; i < _errorHandlers.length; i++) _prevErrorHandlers[i] = _errorHandlers[i];
  public void setErrorHandler(int mask, Callback fun)  {    if ((mask & E_ERROR) != 0)      _errorHandlers[B_ERROR] = fun;        if ((mask & E_WARNING) != 0)      _errorHandlers[B_WARNING] = fun;        if ((mask & E_PARSE) != 0)      _errorHandlers[B_PARSE] = fun;        if ((mask & E_NOTICE) != 0)      _errorHandlers[B_NOTICE] = fun;        if ((mask & E_USER_ERROR) != 0)      _errorHandlers[B_USER_ERROR] = fun;        if ((mask & E_USER_WARNING) != 0)      _errorHandlers[B_USER_WARNING] = fun;        if ((mask & E_USER_NOTICE) != 0)      _errorHandlers[B_USER_NOTICE] = fun;        if ((mask & E_STRICT) != 0)      _errorHandlers[B_STRICT] = fun;  }