protected function aggregateData()
    {
        $data = [
            'iso_code'            => $this->isoCode,
            'name'                => $this->name,
            'symbol'              => $this->symbol,
            'subunit'             => $this->subunit,
            'symbol_first'        => $this->symbolFirst,
            'html_entity'         => $this->htmlEntity,
            'decimal_mark'        => $this->decimalMark,
            'thousands_separator' => $this->thousandsSeparator,
            'iso_numeric'         => $this->isoNumeric,
        ];

        if (!is_null($this->alternateSymbols)) {
            $data['alternate_symbols'] = $this->alternateSymbols;
        }

        if (!is_null($this->disambiguateSymbol)) {
            $data['disambiguate_symbol'] = $this->disambiguateSymbol;
        }

        return $data;
    }