Implement GetBanAsync (#1056)

src/Discord.Net.Core/Entities/Guilds/IGuild.cs

@@ -1,4 +1,4 @@
-using Discord.Audio;
+using Discord.Audio;
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
@@ -66,6 +66,24 @@ namespace Discord
 
         /// <summary> Gets a collection of all users banned on this guild. </summary>
         Task<IReadOnlyCollection<IBan>> GetBansAsync(RequestOptions options = null);
+        /// <summary>
+        ///     Gets a ban object for a banned user.
+        /// </summary>
+        /// <param name="user">The banned user.</param>
+        /// <returns>
+        ///     An awaitable <see cref="Task"/> containing the ban object, which contains the user information and the
+        ///     reason for the ban; <see langword="null"/> if the ban entry cannot be found.
+        /// </returns>
+        Task<IBan> GetBanAsync(IUser user, RequestOptions options = null);
+        /// <summary>
+        ///     Gets a ban object for a banned user.
+        /// </summary>
+        /// <param name="userId">The snowflake identifier for the banned user.</param>
+        /// <returns>
+        ///     An awaitable <see cref="Task"/> containing the ban object, which contains the user information and the
+        ///     reason for the ban; <see langword="null"/> if the ban entry cannot be found.
+        /// </returns>
+        Task<IBan> GetBanAsync(ulong userId, RequestOptions options = null);
         /// <summary> Bans the provided user from this guild and optionally prunes their recent messages. </summary>
         /// <param name="pruneDays">The number of days to remove messages from this user for - must be between [0, 7]</param>
         Task AddBanAsync(IUser user, int pruneDays = 0, string reason = null, RequestOptions options = null);
@@ -135,4 +153,4 @@ namespace Discord
         /// <summary> Deletes an existing emote from this guild. </summary>
         Task DeleteEmoteAsync(GuildEmote emote, RequestOptions options = null);
     }
-}
+}