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YandexMusic.API/Requests/Account/YGetAuthLoginUserBuilder.cs

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+using System.Net;
+
+using YandexMusic.API.Common;
+using YandexMusic.API.Models.Account;
+using YandexMusic.API.Requests.Common;
+using YandexMusic.API.Requests.Common.Attributes;
+
+namespace YandexMusic.API.Requests.Account
+{
+    [YPassportRequest(WebRequestMethods.Http.Post, "registration-validations/auth/multi_step/start")]
+    internal class YGetAuthLoginUserBuilder : YRequestBuilder<YAuthTypes, (string token, string login)>
+    {
+        public YGetAuthLoginUserBuilder(YandexMusicApi yandex, AuthStorage auth) : base(yandex, auth)
+        {
+        }
+
+        protected override HttpContent GetContent((string token, string login) tuple)
+        {
+            return new FormUrlEncodedContent(new Dictionary<string, string> {
+                { "csrf_token", tuple.token },
+                { "login", tuple.login }
+            });
+        }
+    }
+}