public TripleName TryEnsureNamespace(TripleName name)
{
if(name.Namespace == null)
{
if (TripleName.PrefixesAndNamespaces.ContainsKey(name.Prefix))
return new TripleName(TripleName.PrefixesAndNamespaces[name.Prefix], name.Prefix, name.Name);
var tr = TriplePrefixes.FirstOrDefault(x => x.Prefix == name.Prefix);
return tr != null ? new TripleName(tr.Namespace, name.Prefix, name.Name) : name;
} else
return name;
}