original_string: private static function getFirstIP($proxyString = ''): ?string
      {
          \preg_match('/^(([0-9]{1,3}\.){3}[0-9]{1,3})/', $proxyString, $matches);
          return (\is_array($matches) && isset($matches[1])) ? $matches[1] : null;
      }
code: private static function getFirstIP($proxyString = ''): ?string
      {
          \preg_match('/^(([0-9]{1,3}\.){3}[0-9]{1,3})/', $proxyString, $matches);
          return (\is_array($matches) && isset($matches[1])) ? $matches[1] : null;
      }
code_tokens: private static function getFirstIP ( $ proxyString = '' ) : ? string { \ preg_match ( '/^(([0-9]{1,3}\.){3}[0-9]{1,3})/' , $ proxyString , $ matches ) ; return ( \ is_array ( $ matches ) && isset ( $ matches [ 1 ] ) ) ? $ matches [ 1 ] : null ; }
docstring: Checks for first IP in proxy string and returns it
  
  @param string $proxyString
  @return null|string
docstring_tokens: Checks for first IP in proxy string and returns it