anchor.diff:  `NimbusAuthorizationCodeTokenResponseClient` uses the https://connect2id.com/products/nimbus-oauth-openid-connect-sdk[Nimbus OAuth 2.0 SDK] internally.
   
   If you would like to provide a custom implementation of `OAuth2AccessTokenResponseClient`
  -that uses Spring Framework 5 reactive `WebClient` for initiating requests to the token endpoint,
  +that uses Spring Framework 5 reactive `WebClient` for initiating requests to the Token Endpoint,
   configure it as shown in the following example:
   
   [source,java]
  
positive.code: `ClientRegistration` is a representation of a client registered with an OAuth 2.0 or OpenID Connect 1.0 Provider.
  
  A client registration holds information, such as client id, client secret,
  authorization grant type, redirect URI, scope(s), authorization URI, _token URI, and other details.
  
  `ClientRegistration` and its properties are defined as follows:
  
  
negative.code: 
  [NOTE]
  `OAuth2UserService` is responsible for obtaining the user attributes
  of the end user (the resource owner) from the UserInfo Endpoint (by using the
  access token granted to the client during the authorization flow)
  and return an `AuthenticatedPrincipal` in the form of an `OidcUser`.
  
  