private async Task<Maybe<TreeID>> getRoot()
{
// First, attempt to get the current user's staging area and use its TreeID:
// TODO.
// Fall back on the commit from 'system/published' ref and use its TreeID:
var erfcm = await SystemContext.cmrepo.GetCommitByRefName((RefName)"system/published");
if (erfcm.HasErrors) return Maybe<TreeID>.Nothing;
return erfcm.Value.Item2.TreeID;
}