get regExpGlobal() {
        if (!this.hasRegExp) {
            const regExpStr = this.getRegExpStr();
            this._regExpGlobal = regExpStr ? new RegExp(regExpStr, 'gi') : null;
            this.hasRegExp = true;
        }
        return this._regExpGlobal;
    }
Returns null if there is no such regexp (because there are no brackets).