message: Updated the example to the correct return type
diff: @@ -18,7 +18,7 @@ class MyAuthenticationProvider implements AuthenticationProvider {
  * This should return a Promise that resolves to an accessToken (in case of success) or rejects with error (in case of failure)
  * Basically this method will contain the implementation for getting and refreshing accessTokens
  */
  - public async getAccessToken(): Promise<any> {}
  + public async getAccessToken(): Promise<string> {}
  }
  ```
  