.collect { it.trim() }
            .grep { !it.isEmpty() }
    }

    static List<String> parentCommitsOf(String commit) {
        return getStdout("git show --format=%P --no-patch $commit")
            .split(" ").collect { it.trim() }.grep { !it.isEmpty() }
    }

    @groovy.transform.ToString
    static class ExecResult {
        String stdout