### Sample Request with GET Query Parameter

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

An example of a GET request including the access_token as a query parameter.

```http
GET /yconnect/v2/attribute?access_token=SlAV32hkKG HTTP/1.1
Host: userinfo.yahooapis.jp
```

--------------------------------

### OpenID Configuration Request Sample

Source: https://developer.yahoo.co.jp/yconnect/v2/hybrid/configuration.html

Example of how to request the OpenID configuration. This includes the URL and the HTTP GET request.

```http
https://auth.login.yahoo.co.jp/yconnect/v2/.well-known/openid-configuration

GET /yconnect/v2/.well-known/openid-configuration HTTP/1.1
Host: auth.login.yahoo.co.jp
```

--------------------------------

### Response Sample: User Identifier (GUID)

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'sub' parameter, representing a user identifier in GUID format.

```json
"KVNE5DZLWIY4Y57TRDLURJOOEU"
```

--------------------------------

### Authorization Endpoint Request Sample

Source: https://developer.yahoo.co.jp/yconnect/v2/authorization_code/authorization.html

Example GET request to the Authorization endpoint, demonstrating the inclusion of essential parameters.

```http
GET /yconnect/v2/authorization?
response_type=code
&client_id=dj0zaiZpPXNYeG5tRXJKUVVlLSZzPWNvbnN1bWVyc2VjcmV0Jng9ZWU-
&redirect_uri=https%3A%2F%2Fexample.org%2Fcb
&scope=openid%20profile
&state=af0ifjsldkj HTTP/1.1
```

--------------------------------

### Authorization Code Flow Example

Source: https://developer.yahoo.co.jp/yconnect/v2/java_sdk

A Java code example demonstrating how to use the YConnectClient to initiate the Authorization Code flow, including setting parameters and generating the authorization URI.

```java
// Application ID and Secret
private final static String clientId = "YOUR_APPLICATION_ID";
private final static String clientSecret = "YOUR_SECRET";

// Callback URL (registered when issuing the application ID)
private static final String redirectUri = "https://YOUR_CALLBACK_HOST/YConnectServlet/YConnectServlet";

// Specify a random string for verification between request and callback
String state = "5Ye65oi744KKT0vjgafjgZnjgojjgIHlhYjovKnjg4M=";
// Specify a random string for replay attack prevention
String nonce = "SUTljqjjga8uLi7jgrrjg4Plj4vjgaDjgoc=";
// Specify a random string for token replacement attack prevention as Code Verifier
// https://datatracker.ietf.org/doc/html/rfc7636#section-4.1
String plainCodeChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM";

// Get YConnect instance
YConnectClient yconnect = new YConnectClient();

// Initialize parameters
String responseType = OAuth2ResponseType.CODE;
String display = OIDCDisplay.DEFAULT;
String[] prompt = { OIDCPrompt.DEFAULT };
String[] scope = { OIDCScope.OPENID, OIDCScope.PROFILE,
        OIDCScope.EMAIL, OIDCScope.ADDRESS };

// Set parameters
yconnect.init(clientId, redirectUri, state, responseType, display, prompt, scope, nonce, maxAge, plainCodeChallenge);
URI uri = yconnect.generateAuthorizationUri();

// Redirect to the Authorization endpoint (display consent screen)
response.sendRedirect(uri.toString());

/*
 * In actual development, generate random strings for state, nonce, and plainCodeChallenge
 * instead of using fixed strings, and save them to a database or other storage.
 * state is required when receiving the callback URL from the Authorization endpoint.
 * nonce is required when decrypting the ID token.
 * plainCodeChallenge is required when requesting the Token endpoint.
 *
 * plainCodeChallenge will be converted to a Code Challenge within the SDK and included in the query parameters.
 * For details on each parameter value, please refer to the Authorization Endpoint documentation.
 */
```

--------------------------------

### Sample Request with Authorization Header

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

An example of a GET request using the Authorization header with a Bearer Token.

```http
GET /yconnect/v2/attribute HTTP/1.1
Host: userinfo.yahooapis.jp
Authorization: Bearer SlAV32hkKG
```

--------------------------------

### Access Token Parameter Example

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Shows how to pass the Access Token as a GET query parameter. Note: This method will be deprecated after September 1, 2026.

```http
access_token=SlAV32hkKG
```

--------------------------------

### Token Response Example

Source: https://developer.yahoo.co.jp/yconnect/v2/hybrid/token.html

This is an example of a successful response when a token is acquired.

```APIDOC
## Token Response Example

### Description
This is an example of a successful response when a token is acquired.

### Response
#### Success Response (200)
- **access_token** (string) - The acquired access token.
- **token_type** (string) - The type of the token, typically 'Bearer'.
- **expires_in** (integer) - The time in seconds until the token expires.

#### Response Example
```json
{
    "access_token": "SlAV32hkKG",
    "token_type": "Bearer",
    "expires_in": 3600
}
```
```

--------------------------------

### Authorization Header Example

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Demonstrates the format for the Authorization header, using a Bearer Token.

```http
Authorization: Bearer SlAV32hkKG
```

--------------------------------

### Authorization Endpoint Request Sample

Source: https://developer.yahoo.co.jp/yconnect/v2/implicit/authorization.html

Example of a GET request to the Authorization endpoint, demonstrating the inclusion of various parameters for authentication and authorization.

```http
GET /yconnect/v2/authorization?
response_type=id_token%20token
&client_id=dj0zaiZpPXNYeG5tRXJKUVVlLSZzPWNvbnN1bWVyc2VjcmV0Jng9ZWU-
&redirect_uri=https%3A%2F%2Fclient.example.org%2Fcb
&scope=openid%20profile
&state=af0ifjsldkj
&nonce=n-0S6_WzA2Mj HTTP/1.1
```

--------------------------------

### LoginManager Setup

Source: https://developer.yahoo.co.jp/yconnect/v2/client_app/ios

Initialize the LoginManager with your Client ID and custom URI scheme. This should be called at the application launch.

```APIDOC
## LoginManager Setup

### Description
Initialize the LoginManager with your Client ID and custom URI scheme. This should be called at the application launch.

### Method
`LoginManager.setup(clientId: String, redirectUri: URL)`

### Parameters
- **clientId** (String) - Your pre-issued Client ID.
- **redirectUri** (URL) - The custom URI scheme for your application, typically in the format `yj-xxxxx://`.

### Request Example
```swift
import YJLoginSDK

let clientId = "dj00zaiZpPXNYeG5tRXJVVlLzPuWNMvbnN1bWVyc2VjcmV0JnXXXXX-"
let redirectUri = URL(string: "yj-xxxxx:/")!

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    LoginManager.shared.setup(clientId: clientId, redirectUri: redirectUri)
    return true
}
```
```

--------------------------------

### Response Sample: Full Name

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'name' parameter, returning the user's full name.

```json
"矢風太郎"
```

--------------------------------

### Authorization Endpoint GET Request Sample

Source: https://developer.yahoo.co.jp/yconnect/v2/hybrid/authorization.html

A sample GET request to the Authorization endpoint, demonstrating the inclusion of various parameters like response_type, client_id, redirect_uri, scope, nonce, and state.

```http
GET /yconnect/v2/authorization?
response_type=code%20id_token
&client_id=dj0zaiZpPXNYeG5tRXJKUVVlLSZzPWNvbnN1bWVyc2VjcmV0Jng9ZWU-
&redirect_uri=https%3A%2F%2F
example.org%2Fcb
&scope=openid%20profile
&nonce=n-0S6_WzA2Mj
&state=af0ifjsldkj HTTP/1.1
Host: auth.login.yahoo.co.jp
```

--------------------------------

### Callback Parameter Example

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Illustrates the use of the 'callback' parameter for JSONP responses.

```http
callback=success
```

--------------------------------

### Response Sample: Locale

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'locale' parameter, which is fixed to 'ja-JP'.

```json
"ja-JP"
```

--------------------------------

### LoginManager Setup

Source: https://developer.yahoo.co.jp/yconnect/v2/client_app/android

Initialize the LoginManager with your Client ID and Redirect URI. This must be called before any other LoginManager methods. It is recommended to call this at application startup.

```APIDOC
## LoginManager Setup

### Description
Initialize the LoginManager with your Client ID and Redirect URI. This must be called before any other LoginManager methods. It is recommended to call this at application startup.

### Code Example
```kotlin
val clientId = "dj00zaiZpPXNYeG5tRXJVVlLzPuWNMvbnN1bWVyc2VjcmV0JnXXXXX-"
val redirectUri = "android-app://$packageName/yj-example//"

LoginManager.setup(clientId, redirectUri)
```
```

--------------------------------

### Response Sample: First Name

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'given_name' parameter, returning only the user's first name.

```json
"太郎"
```

--------------------------------

### Error Response Example

Source: https://developer.yahoo.co.jp/yconnect/v2/hybrid/token.html

This is an example of an error response when token acquisition fails.

```APIDOC
## Error Response Example

### Description
This is an example of an error response when token acquisition fails.

### Response
#### Error Response (400)
- **error** (string) - The error code.
- **error_description** (string) - A description of the error.
- **error_code** (integer) - A code for error identification.

#### Response Example
```json
{
    "error": "invalid_request",
    "error_description": "Unsupported response_type value",
    "error_code": 1000
}
```

### Error Details
For more details on errors, please refer to: https://tools.ietf.org/html/rfc6749#page-45
```

--------------------------------

### ID Token Header Example

Source: https://developer.yahoo.co.jp/yconnect/v2/id_token.html

This is an example of the Header section of an ID Token, specifying the token type, signing algorithm, and key ID.

```json
{
  "typ": "JWT",
  "alg": "RS256",
  "kid": "0cc175b9c0f1b6a831c399e269772661"
}
```

--------------------------------

### OpenID Configuration Response Example

Source: https://developer.yahoo.co.jp/yconnect/v2/authorization_code/configuration.html

This is a sample JSON response from the OpenID Configuration endpoint, detailing supported features and endpoints.

```json
HTTP/1.1 200 OK
Content-Type: application/json
Date: Wed, 11 May 2016 07:54:16 GMT
Expires: Wed, 11 May 2016 08:54:16 GMT
Cache-Control: public, max-age=3600

{
  "issuer": "https://auth.login.yahoo.co.jp/yconnect/v2/",
  "authorization_endpoint": "https://auth.login.yahoo.co.jp/yconnect/v2/authorization",
  "token_endpoint": "https://auth.login.yahoo.co.jp/yconnect/v2/token",
  "userinfo_endpoint": "https://userinfo.yahooapis.jp/yconnect/v2/attribute",
  "jwks_uri": "https://auth.login.yahoo.co.jp/yconnect/v2/jwks",
  "response_types_supported": [
    "code",
    "token",
    "id_token",
    "code token",
    "code id_token",
    "token id_token",
    "code token id_token"
  ],
  "subject_types_supported": [
    "public",
    "pairwise"
  ],
  "id_token_signing_alg_values_supported": [ "RS256" ],
  "scopes_supported": [
    "openid",
    "email",
    "profile",
    "address"
  ],
  "token_endpoint_auth_methods_supported": [
    "client_secret_post",
    "client_secret_basic"
  ],
  "claims_supported": [
    "sub",
    "name",
    "given_name",
    "family_name",
    "email",
    "email_verified",
    "gender",
    "birthdate",
    "zoneinfo",
    "locale",
    "address",
    "iss",
    "aud",
    "exp",
    "iat",
    "nickname",
    "picture"
  ],
  "display_values_supported": [
    "page",
    "popup",
    "touch"
  ],
  "service_documentation": "https://developer.yahoo.co.jp/yconnect/",
  "claims_locales_supported": [ "ja-JP" ],
  "ui_locales_supported": [ "ja-JP" ],
  "op_policy_uri": "https://developer.yahoo.co.jp/yconnect/v2/guideline.html",
  "op_tos_uri": "https://developer.yahoo.co.jp/yconnect/v2/guideline.html"
}
```

--------------------------------

### Response Sample: Address - Formatted

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'address.formatted' parameter, returning a combined string of prefecture and city/municipality.

```json
"東京都千代田区"
```

--------------------------------

### Response Sample: Time Zone

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'zoneinfo' parameter, which is fixed to 'Asia/Tokyo'.

```json
"Asia/Tokyo"
```

--------------------------------

### Response Sample: User Identifier (PPID)

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'sub' parameter, representing a user identifier in PPID format.

```json
"xHOs7gRnw2kq6Nd2nMDYg0aAwxLbZmJky4OMrA8v4-7EYZZS00"
```

--------------------------------

### Response Sample: Last Name

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'family_name' parameter, returning only the user's last name.

```json
"矢風"
```

--------------------------------

### Response Sample: Address - Region

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'address.region' parameter, returning the user's registered prefecture.

```json
"東京都"
```

--------------------------------

### Response Sample: First Name (Kana)

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'given_name#ja-Kana-JP' parameter, returning the phonetic reading (Kana) of the user's first name.

```json
"タロウ"
```

--------------------------------

### Response Sample: Address - Postal Code

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'address.postal_code' parameter, returning the user's registered postal code.

```json
"1028282"
```

--------------------------------

### Response Sample: Email Address

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'email' parameter, returning the user's primary email address. This is not a unique identifier.

```json
"yconnect@example.com"
```

--------------------------------

### Initialize LoginManager with Client ID and Redirect URI

Source: https://developer.yahoo.co.jp/yconnect/v2/client_app/android

Call LoginManager.setup() with your Client ID and prepared redirect URI before executing other SDK methods. It's recommended to do this at app startup.

```kotlin
val clientId = "dj00zaiZpPXNYeG5tRXJVVlLzPuWNMvbnN1bWVyc2VjcmV0JnXXXXX-"
val redirectUri = "android-app://$packageName/yj-example//"

LoginManager.setup(clientId, redirectUri)
```

--------------------------------

### JWKS Endpoint Request Sample

Source: https://developer.yahoo.co.jp/yconnect/v2/authorization_code/jwks.html

Example of a GET request to the JWKS endpoint.

```http
https://auth.login.yahoo.co.jp/yconnect/v2/jwks

GET /yconnect/v2/jwks HTTP/1.1
Host: auth.login.yahoo.co.jp
```

--------------------------------

### Configure Login Button with Scopes and Parameters

Source: https://developer.yahoo.co.jp/yconnect/v2/client_app/android

Set up a LoginButton by assigning scopes, nonce, codeChallenge, and optionalParameters. Assign 'this' as the listener if the activity implements LoginListener.

```kotlin
// ログイン実行用のボタンを設定
findViewById<LoginButton>(R.id.login_button_white).also {
	it.scopes = scopes
	it.nonce = nonce
	it.codeChallenge = codeChallenge
	it.optionalParameters = optionalParameters
	it.listener = this
}
```

--------------------------------

### ID Token Payload Example

Source: https://developer.yahoo.co.jp/yconnect/v2/id_token.html

This is an example of the Payload section of an ID Token, containing user identification, issuer, audience, and expiration details.

```json
{
  "iss": "https://auth.login.yahoo.co.jp/yconnect/v2",
  "sub": "KVNE5DZLWIY4Y57TRDLURJOOEU",
  "aud": [ "dj0zaiZpPWxCUTczV01KazczNSZzPWNvbnN1bWVyc2VjcmV0Jng9NDc-" ],
  "exp": 1453618036,
  "iat": 1453272436,
  "auth_time": 1453271436,
  "nonce": "n-0S6_WzA2Mj",
  "amr": [ "pwd" ],
  "at_hash": "SjjfaAWSdWEvSDfASCmonm",
  "c_hash": "LDktKdoQak3Pk0cnXxCltA"
}
```

--------------------------------

### Setup LoginManager in AppDelegate

Source: https://developer.yahoo.co.jp/yconnect/v2/client_app/ios

Set up the LoginManager with your Client ID and custom URI scheme at the application launch. This is a required step before using other SDK features.

```swift
let clientId = "dj00zaiZpPXNYeG5tRXJVVlLzPuWNMvbnN1bWVyc2VjcmV0JnXXXXX-"
let redirectUri = URL(string: "yj-xxxxx:/")!

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    LoginManager.shared.setup(clientId: clientId, redirectUri: redirectUri)
    return true
}
```

--------------------------------

### Response Sample: Profile Picture URL

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'picture' parameter, returning the URL for the user's profile image. Note: Currently returns a fixed value.

```json
"https://dummy.img.yahoo.co.jp/example.png"
```

--------------------------------

### Response Sample: Display Name

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'nickname' parameter, returning the user's chosen display name. Note: Currently returns a fixed value.

```json
"やふうたろう"
```

--------------------------------

### URL Query Method (GET requests only)

Source: https://developer.yahoo.co.jp/yconnect/v2/api_access.html

This method is suitable for scenarios where including the Access Token in the HTTP header is difficult, such as when client applications operate within a web browser (JavaScript). The Access Token is appended to the URL query parameters for GET requests. Note: This method will be unavailable after September 1, 2026.

```APIDOC
## GET /path/to/webEndPoint

### Description
Sends a GET request with the Access Token included in the URL query parameters.

### Method
GET

### Endpoint
/path/to/webEndPoint?access_token=[access_token]&param=var

### Query Parameters
- **access_token** (string) - Required - The Access Token for authentication.
- **param** (string) - Required - Example parameter.

### Request Example
```http
GET /yconnect/v2/attribute?access_token=SlAV32hkKG HTTP/1.1
Host: userinfo.yahooapis.jp
```
```

--------------------------------

### Response Sample: Address - Locality

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'address.locality' parameter, returning the user's registered city/municipality.

```json
"千代田区"
```

--------------------------------

### Response Sample: Address - Country Code

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'address.country' parameter, returning the 2-letter country code.

```json
"JP"
```

--------------------------------

### Response Sample: Birth Year

Source: https://developer.yahoo.co.jp/yconnect/v2/userinfo.html

Example of the 'birthdate' parameter, returning only the year of birth as a 4-digit number.

```json
"1986"
```

--------------------------------

### Generate Login Button with JavaScript SDK

Source: https://developer.yahoo.co.jp/yconnect/v2/javascript_sdk

Use this script to initialize the login button and configure authorization, autofill, and callback functions. Ensure to replace placeholder values for clientId and redirectUri. The SDK supports Implicit and Authorization Code flows.

```javascript
<span class="yconnectLogin"></span>  
  
<script type="text/javascript">  
window.yconnectInit = function() {  
    YAHOO.JP.yconnect.Authorization.init({  
        button: {    // ボタンに関しては下記URLを参考に設定してください  
                     // https://developer.yahoo.co.jp/yconnect/loginbuttons.html  
            format: "image",  
            type: "a",  
            textType:"a",  
            width: 196,  
            height: 38,  
            className: "yconnectLogin"  
        },  
        authorization: {  
            clientId: "",    // 登録したClient IDを入力してください  
            redirectUri: "", // 本スクリプトを埋め込むページのURLを入力してください  
            scope: "openid",  
            windowWidth: "500",  
            windowHeight: "400"  
        },  
        autofill: {  
            // 属性パラメーター: "属性情報を挿入したいフォーム要素のID名"  
            // name: "name",  
            // email: "email",  
            // address: "address"  
        },  
        onSuccess: function(res) {  
            // 正常時のコールバック関数  
            // res変数に各属性情報が格納されます  
        },  
        onError: function(res) {  
            // エラー発生時のコールバック関数  
        },  
        onCancel: function(res) {  
            // 同意キャンセルされた時のコールバック関数  
        }  
    });  
};
(function(){  
var fs = document.getElementsByTagName("script")[0], s = document.createElement("script");  
s.setAttribute("src", "https://s.yimg.jp/images/login/yconnect/auth/2.0.4/auth-min.js");  
fs.parentNode.insertBefore(s, fs);
})();  
</script>
```

--------------------------------

### Response Sample for New Access Token Acquisition

Source: https://developer.yahoo.co.jp/yconnect/v2/base/token.html

Example JSON response when a new access token is successfully acquired. Includes access_token, token_type, refresh_token, expires_in, and id_token.

```json
HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-store
Pragma: no-cache

{
  "access_token": "SlAV32hkKG",
  "token_type": "Bearer",
  "refresh_token": "8xLOxBtZp8",
  "expires_in": 3600,
  "id_token": "eyJhbGciOiJSUzI1NiIsImtpZCI6IjFlOWdkazcifQ.ewogImlzcyI6ICJodHRwOi8vc2VydmVyLmV4YW1wbGUuY29tIiwKICJzdWIiOiAiMjQ4Mjg5NzYxMDAxIiwKICJhdWQiOiAiczZCaGRSa3F0MyIsCiAibm9uY2UiOiAibi0wUzZfV3pBMk1qIiwKICJleHAiOiAxMzExMjgxOTcwLAogImlhdCI6IDEzMTEyODA5NzAKfQ.ggW8hZ1EuVLuxNuuIJKX_V8a_OMXzR0EHR9R6jgdqrOOF4daGU96Sr_P6qJp6IcmD3HP99Obi1PRs-cwh3LO-p146waJ8IhehcwL7F09JdijmBqkvPeB2T9CJNqeGpe-gccMg4vfKjkM8FcGvnzZUN4_KSP0aAp1tOJ1zZwgjxqGByKHiOtX7TpdQyHE5lcMiKPXfEIQILVq0pc_E2DzL7emopWoaoZTF_m0_N0YzFC6g6EJbOEoRoSK5hoDalrcvRYLSrQAZZKflyuVCyixEoV9GfNQC3_osjzw2PAithfubEEBLuVVk4XUVrWOLrLl0nx7RkKU8NXNHq-rvKMzqg"
}
```

--------------------------------

### OpenID Configuration Endpoint Request

Source: https://developer.yahoo.co.jp/yconnect/v2/authorization_code/configuration.html

Use this URL to retrieve the OpenID configuration. Only the GET method is supported.

```http
URL： https://auth.login.yahoo.co.jp/yconnect/v2/.well-known/openid-configuration
サポートするHTTPメソッド： GET
```

```http
https://auth.login.yahoo.co.jp/yconnect/v2/.well-known/openid-configuration

GET /yconnect/v2/.well-known/openid-configuration HTTP/1.1
Host: auth.login.yahoo.co.jp
```

--------------------------------

### Initialize YConnectClient Class

Source: https://developer.yahoo.co.jp/yconnect/v2/php_sdk

Constructor for the YConnectClient class, which requires a ClientCredential object.

```php
public YConnectClient::__construct(ClientCredential $clientCred)
```

--------------------------------

### Initialize ClientCredential and YConnectClient

Source: https://developer.yahoo.co.jp/yconnect/v2/php_sdk

This snippet demonstrates how to initialize the ClientCredential and YConnectClient classes, which are essential for interacting with the Yahoo! ID連携 API.

```APIDOC
## Initialize ClientCredential and YConnectClient

### Description
Initializes the necessary client credentials and the main client object for interacting with the Yahoo! ID連携 service.

### Usage
```php
use YConnect\Credential\ClientCredential;
use YConnect\YConnectClient;

// Application ID and secret obtained from Yahoo! Developer Network
$client_id = "YOUR_APPLICATION_ID";
$client_secret = "YOUR_SECRET";

// Create a ClientCredential instance
$cred = new ClientCredential($client_id, $client_secret);

// Create a YConnectClient instance using the credentials
$client = new YConnectClient($cred);
```
```

--------------------------------

### OpenID Configuration Response Sample

Source: https://developer.yahoo.co.jp/yconnect/v2/hybrid/configuration.html

A sample JSON response from the OpenID Configuration endpoint. It details supported endpoints, response types, scopes, claims, and other configuration parameters.

```json
HTTP/1.1 200 OK
Content-Type: application/json
Date: Wed, 11 May 2016 07:54:16 GMT
Expires: Wed, 11 May 2016 08:54:16 GMT
Cache-Control: public, max-age=3600

{
  "issuer": "https://auth.login.yahoo.co.jp/yconnect/v2/",
  "authorization_endpoint": "https://auth.login.yahoo.co.jp/yconnect/v2/authorization",
  "token_endpoint": "https://auth.login.yahoo.co.jp/yconnect/v2/token",
  "userinfo_endpoint": "https://userinfo.yahooapis.jp/yconnect/v2/attribute",
  "jwks_uri": "https://auth.login.yahoo.co.jp/yconnect/v2/jwks",
  "response_types_supported": [
    "code",
    "token",
    "id_token",
    "code token",
    "code id_token",
    "token id_token",
    "code token id_token"
  ],
  "subject_types_supported": [ "public" ],
  "id_token_signing_alg_values_supported": [ "RS256" ],
  "scopes_supported": [
    "openid",
    "email",
    "profile",
    "address"
  ],
  "token_endpoint_auth_methods_supported": [
    "client_secret_post",
    "client_secret_basic"
  ],
  "claims_supported": [
    "sub",
    "name",
    "given_name",
    "family_name",
    "email",
    "email_verified",
    "gender",
    "birthdate",
    "zoneinfo",
    "locale",
    "address",
    "iss",
    "aud",
    "exp",
    "iat",
    "nickname",
    "picture"
  ],
  "display_values_supported": [
    "page",
    "popup",
    "touch"
  ],
  "service_documentation": "https://developer.yahoo.co.jp/yconnect/",
  "claims_locales_supported": [ "ja-JP" ],
  "ui_locales_supported": [ "ja-JP" ],
  "op_policy_uri": "https://developer.yahoo.co.jp/yconnect/v2/guideline.html",
  "op_tos_uri": "https://developer.yahoo.co.jp/yconnect/v2/guideline.html"
}
```