public AzureAdOAuthHandler(ClaimProvider issuer)
: base(issuer)
{
if (issuer == null)
throw new ArgumentNullException("issuer");
this.issuer = issuer;
_appId = this.issuer.Parameters["clientId"];
_secretKey = this.issuer.Parameters["key"];
_graphApiEndpoint = this.issuer.Parameters["graphApiEndpoint"];
_tokenEndpoint = this.issuer.Parameters["tokenEndpoint"];
_authorizationEndpoint = this.issuer.Parameters["authorizationEndpoint"];
_graphApiVersion = this.issuer.Parameters["graphApiVersion"];
}