How to Upload multiple Document (bulk) in Document DB

I have Documents list(object) that object has multiple documents i.e. Json records are present but while I try to upload that Bunches of Document(Records) it not upload on document DB but while I upload Single Document records it upload succesfully.

  List<MyModelClass> listObj = new List<MyModelClass>();
  Document doc = await DocumentClient.CreateDocumentAsync("dbs/" + DocumentDatabase.Id + "/colls/" + DocumentCollection.Id, listObj);

above code is not working.....

   foreach (var item in listObj )
    {
      Document doc = await Client.CreateDocumentAsync("dbs/" + DocumentDatabase.Id + "/colls/" + DocumentCollection.Id, item);
    }

This code is working for me.....

 Syntax : CreateDocumentAsync(String, Object, RequestOptions, Boolean)
 Object :- Document object // I Know it as per syntax it need to be "Document Type".

I want any Other way to Upload All Document at Once....