public async Task AuthenticateClient(HttpClient client) { using (var tokenTicket = await tokenStore.Get(tokenIdentifier)) { var tokens = tokenTicket.Get(); if (!tokens.HasValidAccessToken) { tokens = await tokenRenewalStrategy.GetTokens(tokens); await tokenTicket.Update(tokens); } client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", tokens.AccessToken); } }