private function getBinaryInteger(File $phpcsFile, $tokens, $stackPtr)
    {
        $length = 2; // PHP < 5.4 T_LNUMBER + T_STRING.

        if ($this->isLowPHPVersion === false) {
            $i = $stackPtr;
            while ($tokens[$i]['code'] === \T_LNUMBER) {
                $i++;
            }
            $length = ($i - $stackPtr);
        }

        return $phpcsFile->getTokensAsString($stackPtr, $length);
    }