function _isReservedShortcuts(normalizedKey) {
        if (!normalizedKey) {
            return false;
        }

        if (_reservedShortcuts.indexOf(normalizedKey) > -1 ||
                _reservedShortcuts.indexOf(normalizedKey.replace("Cmd", "Ctrl")) > -1) {
            return true;
        }

        if (brackets.platform === "mac" && _macReservedShortcuts.indexOf(normalizedKey) > -1) {
            return true;
        }

        return false;
    }
@private

Checks whether the given key combination is a shortcut of a special command
or a Mac system command that the user can't reassign to another command.
@param {!string} normalizedKey A key combination string used for a keyboard shortcut
@return {boolean} true if normalizedKey is a restricted shortcut, false otherwise.