anchor.diff:  ----
   
   [TIP]
  -_id_, _name_, _login_ and _email_ are attributes returned in GitHub's *UserInfo Response*.
  -For detailed information returned from the *UserInfo Endpoint* see the API documentation
  -for https://developer.github.com/v3/users/#get-the-authenticated-user[Get the authenticated user].
  +`id`, `name`, `login`, and `email` are attributes returned in GitHub's UserInfo Response.
  +For detailed information returned from the `UserInfo` endpoint, see the API documentation
  +for https://developer.github.com/v3/users/#get-the-authenticated-user["Get the authenticated user"].
   
   [[oauth2login-advanced-oauth2-user-service]]
   ==== OAuth 2.0 UserService
   
   `DefaultOAuth2UserService` is an implementation of an `OAuth2UserService`
  -that supports standard OAuth 2.0 Provider's.
  +that supports standard OAuth 2.0 Provider instances.
   
   [NOTE]
  -`OAuth2UserService` is responsible for obtaining the user attributes
  -of the end-user (_Resource Owner_) from the UserInfo Endpoint (using the
  -_Access Token_ granted to the client during the _Authorization Flow_)
  -and return an `AuthenticatedPrincipal` in the form of an `OAuth2User`.
  -
  -There may be a use case where you need to define your own implementation of `OAuth2UserService`
  -for standard OAuth 2.0 Provider's if the default implementation does not suit your needs.
  -
  -The following configuration demonstrates how to configure a custom `OAuth2UserService`.
  +`OAuth2UserService` obtains 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 returns an `AuthenticatedPrincipal` in the form of an `OAuth2User`.
  +
  +If the default implementation does not suit your needs, you may need to define your own implementation of `OAuth2UserService`
  +for standard OAuth 2.0 Provider instances.
  +
  +The following configuration demonstrates how to configure a custom `OAuth2UserService`:
   
   [source,java]
   ----
  
positive.code: }
  ----
  
  - Completely override the Auto-configuration by doing both, as per above.
  
  [source,java]
  ----
  
negative.code: [[jc-oauth2login]]
  === OAuth 2.0 Login
  
  The OAuth 2.0 Login feature implements the following use case: "Login with Google" or "Login with GitHub". It provides an application with
  the capability to have users log in to the application by using their existing account at an OAuth 2.0 Provider (e.g. GitHub) or OpenID Connect 1.0 Provider (such as Google).
  
  NOTE: OAuth 2.0 Login is implemented by using the *Authorization Code Grant*, as specified in the https://tools.ietf.org/html/rfc6749#section-4.1[OAuth 2.0 Authorization Framework]
  and http://openid.net/specs/openid-connect-core-1_0.html#CodeFlowAuth[OpenID Connect Core 1.0].
  
  [[jc-oauth2login-sample-boot]]
  