/// <summary>
        /// Sends a token request using the authorization_code grant type.
        /// </summary>
        /// <param name="client">The client.</param>
        /// <param name="request">The request.</param>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <returns></returns>
        public static async Task <TokenResponse> RequestAuthorizationCodeTokenAsync(this HttpMessageInvoker client, AuthorizationCodeTokenRequest request, CancellationToken cancellationToken = default)
        {
            var clone = request.Clone();

            clone.Parameters.AddRequired(OidcConstants.TokenRequest.GrantType, OidcConstants.GrantTypes.AuthorizationCode);
            clone.Parameters.AddRequired(OidcConstants.TokenRequest.Code, request.Code);
            clone.Parameters.AddRequired(OidcConstants.TokenRequest.RedirectUri, request.RedirectUri);
            clone.Parameters.AddOptional(OidcConstants.TokenRequest.CodeVerifier, request.CodeVerifier);

            foreach (var resource in request.Resource)
            {
                clone.Parameters.AddRequired(OidcConstants.TokenRequest.Resource, resource, allowDuplicates: true);
            }

            return(await client.RequestTokenAsync(clone, cancellationToken).ConfigureAwait());
        }
        /// <summary>
        /// Sends a token request using the authorization_code grant type.
        /// </summary>
        /// <param name="client">The client.</param>
        /// <param name="request">The request.</param>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <returns></returns>
        public static async Task <TokenResponse> RequestAuthorizationCodeTokenAsync(this HttpClient client, AuthorizationCodeTokenRequest request, CancellationToken cancellationToken = default)
        {
            request.GrantType = OidcConstants.GrantTypes.AuthorizationCode;

            request.Parameters.AddRequired(OidcConstants.TokenRequest.Code, request.Code);
            request.Parameters.AddRequired(OidcConstants.TokenRequest.RedirectUri, request.RedirectUri);
            request.Parameters.AddOptional(OidcConstants.TokenRequest.CodeVerifier, request.CodeVerifier);

            return(await client.RequestTokenAsync(request, cancellationToken));
        }