*jslint node:true*/
'use strict';
var Client = require("mongodb").MongoClient,
    db;

Client.connect("mongodb://localhost/test").then(function (conn) {
    db = conn;
    var bwt = conn.collection("bwt");
    //return bwt.bulkWrite([{ insertOne: { document: { a: 1 } } }]);
    return new Promise(function (resolve, reject) {
        bwt.bulkWrite([{ insertOne: { document: { a: 1 } } }], function (err, r) {
            if (err) {
                reject(err);
            } else {
                resolve(r);
            }
        });
    });
}).then(function (r) {
    console.log(r.insertedCount); //1
}).catch(function (reason) {
    console.error(reason);
}).then(function () {
    if (db) {
        db.close();
    }
});