rem: EmpathIndex::contains(const QString & key) { _read(); _resetIdleTimer(); return (0 != dict_.find(key)); }
add: bool contains(const QString & key) const { return (0 != dict_.find(key)); }
context: EmpathIndex::contains(const QString & key){    _read();    _resetIdleTimer();    return (0 != dict_.find(key));}