How to get git branch information about each of commit by using 'LibGit2sharp'

I'd like to make 'Commit History Graph' by using libgit2sharp library like below.

There was a similar question in stackoverflow, but I couldn't get the specific answer.

• How do I build a version tree for a Git repository using LibGit2(Sharp)

string path = "c:\github\git-gui-app";
var repo = Repository(path);
var commits = repo.Commits();
var list = new List<CommitItem>();
foreach (var item in commits)
{
    var commitItem = new CommitItem();
    commitItem.Name = item.Message;
    commitItem.Sha = item.Sha;
    commitItem.ParentSha = item.Parents.FirstOrDefault().Sha;
    list.Add(commitItem);
}

foreach (var item in list)
{
    item.BranchInfo = GetBranchInfo(item);
}

...

private BranchItem GetBranchInfo(CommitItem item)
{
    // How to get branch information in current commit?
}

I succeeded in getting the git repository commit information, but I still don't know how to get branch information of each commit.