What is "The build status' unique key" when attempting to get build status?

Question

I am currently attempting to extract the build status of a repository, but have hit the wall of not knowing what the build status' unique key is. I have looked around and can't find the answer.

The error I get is below. I have replaced my hash with SHA1 in the text and I the 'the build status unique key' is just used as I don't know what I should send.

Build status with key 'the build status unique key' for node SHA1 of repository javarequest not found

My test code below works all up until the last line.

// Bitbucket API, this one is for V2
var sharpBucket = new SharpBucketV2();
// authenticate with OAuth2 keys
sharpBucket.OAuth2ClientCredentials(_settings.ConsumerKey, _settings.ConsumerSecret);

//Gets a repo
var repos = sharpBucket.RepositoriesEndPoint().RepositoriesResource("MY WORK SPACE");
var reposList = repos.ListRepositories();
var repo = repos.RepositoryResource(reposList[0].name);

//Build info
var commit = repo.EnumerateCommits().FirstOrDefault();
var info = repo.GetCommit(commit.hash).message;
var buildStatusInfo = repo.GetBuildStatusInfo("SHA1", "build status unique key");