diff --git a/CHANGELOG.md b/CHANGELOG.md
index b32fdd7..d7cc6b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Change Log
 
+## [v4.21.0](https://github.com/plivo/plivo-node/tree/v4.21.0) (2021-08-05)
+- Fixed a Typescript warning about base interpretation.
+- Add retrievable object responses support for [Retrieve a Power pack API](https://www.plivo.com/docs/sms/api/powerpack#retrieve-a-powerpack).
+
 ## [v4.20.1](https://github.com/plivo/plivo-node/tree/v4.20.1) (2021-07-27)
 - Updates to [add a member a multi-party call API](https://www.plivo.com/docs/voice/api/multiparty-call/participants#add-a-participant).
   - Remove validation range for `delay` and `ringtimeout` parameters.
diff --git a/lib/resources/numbers.js b/lib/resources/numbers.js
index ccaec8b..b275123 100644
--- a/lib/resources/numbers.js
+++ b/lib/resources/numbers.js
@@ -1,4 +1,5 @@
 import {
+    PlivoGenericResponse,
     PlivoResource,
     PlivoResourceInterface
 } from '../base';
@@ -271,7 +272,15 @@ export class NumberInterface extends PlivoResourceInterface {
         params.carrier = carrier;
         params.region = region;
 
-        return super.create(params);
+        return new Promise((resolve, reject) => {
+            client('POST', action, params)
+                .then(response => {
+                    resolve(new PlivoGenericResponse(response.body, idField));
+                })
+                .catch(error => {
+                    reject(error);
+                });
+        })
     }
 
     /**
diff --git a/lib/resources/powerpacks.js b/lib/resources/powerpacks.js
index 9e96fed..c04149b 100644
--- a/lib/resources/powerpacks.js
+++ b/lib/resources/powerpacks.js
@@ -40,6 +40,22 @@ export class CreatePowerpackResponse {
     }
 }
 
+export class RetrievePowerpack {
+    constructor(params) {
+            params = params || {};
+            this.apiId = params.apiId;
+            this.applicationId = params.applicationId;
+            this.applicationType = params.applicationType;
+            this.createdOn = params.createdOn;
+            this.localConnect = params.localConnect;
+            this.name = params.name;
+            this.numberPool = params.numberPool;
+            this.numberPriority = params.numberPriority;
+            this.stickySender = params.stickySender;
+            this.uuid = params.uuid;
+        }
+}
+
 export class UpdatePowerpackResponse {
     constructor(params) {
         params = params || {};
@@ -696,9 +712,32 @@ export class PowerpackInterface extends PlivoResourceInterface {
      * @promise {object} return {@link Powerpack} object
      * @fail {Error} return Error
      */
-    get(uuid) {
-        return super.get(uuid);
+     get(uuid) {
+        let errors = validate([{
+            field: 'uuid',
+            value: uuid,
+            validators: ['isRequired']
+        }]);
+
+        if (errors) {
+            return errors;
+        }
+
+        let client = this[clientKey];
+        return new Promise((resolve, reject) => {
+            if (action !== '' && !uuid) {
+                reject(new Error(this[idKey] + ' must be set'));
+            }
+            client('GET', action + (uuid ? uuid + '/' : ''))
+                .then(response => {
+                    resolve(new RetrievePowerpack(response.body, client));
+                })
+                .catch(error => {
+                    reject(error);
+                });
+        });
     }
+    
     /**
      * create Powerpack
      * @method
diff --git a/lib/rest/request-test.js b/lib/rest/request-test.js
index 18e1791..012a817 100644
--- a/lib/rest/request-test.js
+++ b/lib/rest/request-test.js
@@ -1,5 +1,5 @@
-import request from 'request';
 import queryString from 'querystring';
+import request from 'request';
 
 export function Request(config) {
   let auth = 'Basic ' + new Buffer(config.authId + ':' + config.authToken)
@@ -1465,4 +1465,4 @@ export function Request(config) {
       }
     });
   };
-}
+}
\ No newline at end of file
diff --git a/lib/rest/request.js b/lib/rest/request.js
index 94f1c72..67fd730 100644
--- a/lib/rest/request.js
+++ b/lib/rest/request.js
@@ -1,8 +1,9 @@
-import request from 'request';
-import queryString from 'querystring';
 import * as Exceptions from '../utils/exceptions';
 import * as _ from "lodash";
 
+import queryString from 'querystring';
+import request from 'request';
+
 export function Request(config) {
   let auth = 'Basic ' + new Buffer(config.authId + ':' + config.authToken)
     .toString('base64');
@@ -219,4 +220,4 @@ export function Request(config) {
       });
     });
   };
-}
+}
\ No newline at end of file
diff --git a/package-lock.json b/package-lock.json
index 347cb92..d516358 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5591,4 +5591,4 @@
       "dev": true
     }
   }
-}
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index a287d5d..a471bda 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "plivo",
-  "version": "4.20.1",
+  "version": "4.21.0",
   "description": "A Node.js SDK to make voice calls and send SMS using Plivo and to generate Plivo XML",
   "homepage": "https://github.com/plivo/plivo-node",
   "files": [
diff --git a/types/base.d.ts b/types/base.d.ts
index b53c07b..337f69a 100644
--- a/types/base.d.ts
+++ b/types/base.d.ts
@@ -4,8 +4,8 @@ export class PlivoGenericResponse {
 }
 export class PlivoResource {
     constructor(action: string, Klass: Symbol, idField: string, request: any);
-    update(params: object, id: string): Promise<any>;
-    delete(params: object): Promise<any>;
+    // update(params: any, id: any): Promise<any>;
+    delete(params: any): Promise<any>;
     executeAction(task: string, method: string, params: {}, action: string): Promise<any>;
     customexecuteAction(url: string, method?: string, params?: {}): Promise<any>;
     customexecuteGetNumberAction(url: string, method?: string, params?: {}): any;
@@ -13,7 +13,7 @@ export class PlivoResource {
 }
 export class PlivoResourceInterface {
     constructor(action: string, Klass: Symbol, idField: string, request: any);
-    get(id: string, params?: {}): Promise<any>;
-    list(params: object): Promise<any>;
-    create(params: object): Promise<any>;
-}
+    // get(id: any, params?: {}): Promise<any>;
+    // create(params: any): Promise<any>;
+    list(params: any): Promise<any>;
+}
\ No newline at end of file
diff --git a/types/resources/endUsers.d.ts b/types/resources/endUsers.d.ts
index fbdca55..f3efc54 100644
--- a/types/resources/endUsers.d.ts
+++ b/types/resources/endUsers.d.ts
@@ -29,7 +29,7 @@ export class ListEndUsersResponse {
     constructor(params: object);
     apiId: string;
     meta: Object;
-    objects: Array;
+    objects: Array<string>;
 }
 
 /**
diff --git a/types/resources/media.d.ts b/types/resources/media.d.ts
index fe251e5..ca38f5f 100644
--- a/types/resources/media.d.ts
+++ b/types/resources/media.d.ts
@@ -42,7 +42,7 @@ export class MediaInterface extends PlivoResourceInterface {
 	 * @method
 	 * @fail {Error} return Error
 	 */
-    upload(files: Array): Promise<UploadMediaResponse>;
+    upload(files: Array<string>): Promise<UploadMediaResponse>;
     /**
      * Get Media by given id
      * @method
diff --git a/types/resources/messages.d.ts b/types/resources/messages.d.ts
index c709edc..a72264f 100644
--- a/types/resources/messages.d.ts
+++ b/types/resources/messages.d.ts
@@ -23,7 +23,7 @@ export class MessageGetResponse {
 }
 export class MessageListResponse {
 	constructor(params: object);
-    errorCode: string;
+  errorCode: string;
 	fromNumber: string;
 	messageDirection: string;
 	messageState: string;
@@ -34,7 +34,7 @@ export class MessageListResponse {
 	toNumber: string;
 	totalAmount: string;
 	totalRate: string;
-    units: string;
+  units: string;
 	powerpackId: string;
 }
 export class MMSMediaResponse {
@@ -90,7 +90,7 @@ export class MessageInterface extends PlivoResourceInterface {
 		type: string;
 		url: string;
 		method: string;
-		media_urls: Array;
+		media_urls: Array<string>;
 		log: boolean;
 	}): Promise < MessageResponse > ;
 	/**
diff --git a/types/resources/powerpacks.d.ts b/types/resources/powerpacks.d.ts
index 1892aa3..a6d3492 100644
--- a/types/resources/powerpacks.d.ts
+++ b/types/resources/powerpacks.d.ts
@@ -17,6 +17,21 @@ export class CreatePowerpackResponse {
 	stickySender: string;
 	uuid: string;
 }
+
+export class RetrievePowerpack {
+	constructor(params: object);
+	apiId: string;
+	applicationId: string;
+	applicationType: string;
+	createdOn: string;
+	localConnect: string;
+	name: string;
+	numberPool: string;
+	numberPriority: object;
+	stickySender: string;
+	uuid: string;
+}
+
 export class UpdatePowerpackResponse {
 	constructor(params: object);
 	apiId: string;
@@ -179,7 +194,7 @@ export class PowerpackInterface extends PlivoResourceInterface {
      * @promise {object} return {@link Powerpack} object
      * @fail {Error} return Error
      */
-    get(uuid: string): any;
+    get(uuid: string): Promise<RetrievePowerpack>;
     /**
      * create Powerpack
      * @method
@@ -189,7 +204,7 @@ export class PowerpackInterface extends PlivoResourceInterface {
      * @param {string} [params.local_connect]
      * @param {string} [params.application_type]
      * @param {string} [params.application_id]
-     * @promise {object} return {@link PlivoGenericResponse} object
+     * @promise {object} return {@link RetrievePowerpack} object
      * @fail {Error} return Error
      */
     create(name: string, params?: {}): Promise<CreatePowerpackResponse>;
diff --git a/types/rest/request-test.d.ts b/types/rest/request-test.d.ts
index 1f56632..c2221c1 100644
--- a/types/rest/request-test.d.ts
+++ b/types/rest/request-test.d.ts
@@ -1 +1 @@
-export function Request(config: any): (method: string, action: string, params: object) => Promise<any>;
+export function Request(config: any): (method: string, action: string, params: object) => Promise<any>;
\ No newline at end of file
diff --git a/types/rest/request.d.ts b/types/rest/request.d.ts
index 1f56632..c2221c1 100644
--- a/types/rest/request.d.ts
+++ b/types/rest/request.d.ts
@@ -1 +1 @@
-export function Request(config: any): (method: string, action: string, params: object) => Promise<any>;
+export function Request(config: any): (method: string, action: string, params: object) => Promise<any>;
\ No newline at end of file