anchor.diff:  application]. The application must be configured with a callback URL of
   `<master>/oauth2callback/<identityProviderName>`.
   <6> The client secret issued by GitHub.
  +<7> Optional list of organizations. If specified, only GitHub users that are members of 
  +at least one of the listed organizations will be allowed to log in.
   ====
   
   [[Google]]
  
positive.code:       kind: GitHubIdentityProvider
        clientID: ... <5>
        clientSecret: ... <6>
  ----
  <1> This provider name is prefixed to the GitHub numeric user ID to form an
  identity name. It is also used to build the callback URL.
  
negative.code: ====
  Using Google as an identity provider requires users to get a token using
  `<master>/oauth/token/request` to use with command-line tools.
  ====
  
  [WARNING]
  ====
  Using Google as an identity provider allows any Google user to authenticate to your server.
  You can limit authentication to members of a specific hosted domain with the
  `hostedDomain` config attribute, as shown below.
  ====
  
  .Master Configuration Using *GoogleIdentityProvider*
  