private function getCountOfContainingBranches(string $targetCommit) : int
    {
        $numberOfContainingBranches = substr_count(
            $this->processRunner->runAsProcess(
                'git',
                'branch',
                '-a',
                '--contains',
                $targetCommit
            ),
            PHP_EOL
        );

        return $numberOfContainingBranches;
    }