original_string: protected function currencyStringToNumeric($currency)
      {
          if (!in_array(strtolower($currency), array_keys(self::$currencyCodes))) {
              throw new HpsArgumentException(
                  'Currency is not supported',
                  HpsExceptionCodes::INVALID_CURRENCY
              );
          }
          return self::$currencyCodes[strtolower($currency)];
      }
code: protected function currencyStringToNumeric($currency)
      {
          if (!in_array(strtolower($currency), array_keys(self::$currencyCodes))) {
              throw new HpsArgumentException(
                  'Currency is not supported',
                  HpsExceptionCodes::INVALID_CURRENCY
              );
          }
          return self::$currencyCodes[strtolower($currency)];
      }
code_tokens: protected function currencyStringToNumeric ( $ currency ) { if ( ! in_array ( strtolower ( $ currency ) , array_keys ( self :: $ currencyCodes ) ) ) { throw new HpsArgumentException ( 'Currency is not supported' , HpsExceptionCodes :: INVALID_CURRENCY ) ; } return self :: $ currencyCodes [ strtolower ( $ currency ) ] ; }
docstring: Converts a 3-letter currency code to 3-digit ISO 4217 version
  
  @param string $currency currency code
  
  @return string
  @throws \HpsArgumentException
  @raises HpsArgumentException
docstring_tokens: Converts a 3 - letter currency code to 3 - digit ISO 4217 version