How to use the angular-l10n.parseDigits function in angular-l10n

public parseNumber(value: string, options?: L10nNumberFormatOptions, language = this.locale.language): number | null {
        if (value === '' || value == null) return null;

        let format = { minimumIntegerDigits: 1, minimumFractionDigits: 0, maximumFractionDigits: 0 };
        if (options && options.digits) {
            format = { ...format, ...parseDigits(options.digits) };
        }

        let decimalSeparator: string;
        switch (language) {
            case 'it-IT':
                decimalSeparator = ',';
                break;
            default:
                decimalSeparator = '.';
        }

        const pattern = `^-?[\\d]{${format.minimumIntegerDigits},}(\\${decimalSeparator}[\\d]{${format.minimumFractionDigits},${format.maximumFractionDigits}})?$`;
        const regex = new RegExp(pattern);
        return regex.test(value) ? parseFloat(value.replace(decimalSeparator, '.')) : null;
    }