Changed internal types from class to interface

Thanks to  @pfzero
https://github.com/DefinitelyTyped/DefinitelyTyped/issues/7021#issuecomment-179439322

mongodb/mongodb.d.ts

@@ -11,6 +11,7 @@
 declare module "mongodb" {
   import {EventEmitter} from 'events';
   
+  
   // Class documentation : http://mongodb.github.io/node-mongodb-native/2.1/api/MongoClient.html
   export class MongoClient {
     constructor();
@@ -150,7 +151,7 @@ declare module "mongodb" {
     socketOptions?: SocketOptions;
   }
   
-  // Class documentation : http://mongodb.github.io/node-mongodb-native/api-generated/db.html
+  // Class documentation : http://mongodb.github.io/node-mongodb-native/2.1/api/Db.html
   export class Db extends EventEmitter {
     constructor(databaseName: string, serverConfig: Server | ReplSet | Mongos, options?: DbCreateOptions);
 
@@ -322,7 +323,7 @@ declare module "mongodb" {
   }
   
   // http://mongodb.github.io/node-mongodb-native/2.1/api/Admin.html
-  export class Admin {
+  export interface Admin {
     // http://mongodb.github.io/node-mongodb-native/2.1/api/Admin.html#addUser
     addUser(username: string, password: string, callback: MongoCallback<any>): void;
     addUser(username: string, password: string, options?: AddUserOptions): Promise<any>;
@@ -552,7 +553,7 @@ declare module "mongodb" {
   }
 
   // Documentation : http://mongodb.github.io/node-mongodb-native/2.1/api/Collection.html
-  export class Collection {
+  export interface Collection {
     // Get the collection name.
     collectionName: string;
     // Get the full collection namespace.
@@ -871,7 +872,7 @@ declare module "mongodb" {
   }
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/OrderedBulkOperation.html
-  export class OrderedBulkOperation {
+  export interface OrderedBulkOperation {
     length: number;
     //http://mongodb.github.io/node-mongodb-native/2.1/api/OrderedBulkOperation.html#execute
     execute(callback: MongoCallback<BulkWriteResult>): void;
@@ -884,7 +885,14 @@ declare module "mongodb" {
   }
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/BulkWriteResult.html
-  export class BulkWriteResult {
+  export interface BulkWriteResult {
+    ok: boolean;
+    nInserted: number;
+    nUpdated: number;
+    nUpserted: number;
+    nModified: number;
+    nRemoved: number;
+
     getInsertedIds(): Array<Object>;
     getLastOp(): Object;
     getRawResponse(): Object;
@@ -916,7 +924,7 @@ declare module "mongodb" {
   }
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/FindOperatorsOrdered.html
-  export class FindOperatorsOrdered {
+  export interface FindOperatorsOrdered {
     delete(): OrderedBulkOperation;
     deleteOne(): OrderedBulkOperation;
     replaceOne(doc: Object): OrderedBulkOperation;
@@ -926,7 +934,7 @@ declare module "mongodb" {
   }
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/UnorderedBulkOperation.html
-  export class UnorderedBulkOperation {
+  export interface UnorderedBulkOperation {
     //http://mongodb.github.io/node-mongodb-native/2.1/api/UnorderedBulkOperation.html#execute
     execute(callback: MongoCallback<BulkWriteResult>): void;
     execute(options: FSyncOptions): Promise<BulkWriteResult>;
@@ -938,7 +946,7 @@ declare module "mongodb" {
   }
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/FindOperatorsUnordered.html
-  export class FindOperatorsUnordered {
+  export interface FindOperatorsUnordered {
     length: number;
     remove(): UnorderedBulkOperation;
     removeOne(): UnorderedBulkOperation;
@@ -1044,7 +1052,7 @@ declare module "mongodb" {
   export type CursorResult = any | void | boolean;
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/Cursor.html
-  export class Cursor extends EventEmitter implements Readable {
+  export interface Cursor extends Readable, NodeJS.EventEmitter {
 
     sortValue: string;
     timeout: boolean;
@@ -1161,7 +1169,7 @@ declare module "mongodb" {
   export type AggregationCursorResult = any | void;
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/AggregationCursor.html
-  export class AggregationCursor extends EventEmitter implements Readable {
+  export interface AggregationCursor extends Readable, NodeJS.EventEmitter {
     // http://mongodb.github.io/node-mongodb-native/2.1/api/AggregationCursor.html#batchSize
     batchSize(value: number): AggregationCursor;
     // http://mongodb.github.io/node-mongodb-native/2.1/api/AggregationCursor.html#clone
@@ -1225,7 +1233,7 @@ declare module "mongodb" {
   }
   
   //http://mongodb.github.io/node-mongodb-native/2.1/api/CommandCursor.html
-  export class CommandCursor extends EventEmitter implements Readable {
+  export interface CommandCursor extends Readable, NodeJS.EventEmitter {
     // http://mongodb.github.io/node-mongodb-native/2.1/api/CommandCursor.html#batchSize
     batchSize(value: number): CommandCursor;
     // http://mongodb.github.io/node-mongodb-native/2.1/api/CommandCursor.html#clone