protected function examineList(File $phpcsFile, $opener, $closer)
    {
        $start = $opener;
        while (($start = $this->hasTargetInList($phpcsFile, $start, $closer)) !== false) {
            $phpcsFile->addError(
                'Specifying keys in list constructs is not supported in PHP 7.0 or earlier.',
                $start,
                'Found'
            );
        }
    }