protected function parseAmountDecimalSeparator($amount) {
    $decimal_separator_counts = [];
    foreach ($this->decimalSeparators as $decimal_separator) {
      $decimal_separator_counts[$decimal_separator] = \mb_substr_count($amount, $decimal_separator);
    }
    $decimal_separator_counts_filtered = array_filter($decimal_separator_counts);
    if (count($decimal_separator_counts_filtered) > 1 || reset($decimal_separator_counts_filtered) !== FALSE && reset($decimal_separator_counts_filtered) != 1) {
      return FALSE;
    }
    return str_replace($this->decimalSeparators, '.', $amount);
  }