Add support to Retrieve a block ✨

Author: KoditkarVedant

Src/Notion.Client/Api/ApiEndpoints.cs

@@ -19,6 +19,7 @@ public static class UsersApiUrls
 
         public static class BlocksApiUrls
         {
+            public static string Retrieve(string blockId) => $"/v1/blocks/{blockId}";
             public static string RetrieveChildren(string blockId) => $"/v1/blocks/{blockId}/children";
             public static string AppendChildren(string blockId) => $"/v1/blocks/{blockId}/children";
         }

Src/Notion.Client/Api/Blocks/BlocksClient.cs

@@ -47,5 +47,17 @@ public async Task<Block> AppendChildrenAsync(string blockId, BlocksAppendChildre
 
             return await _client.PatchAsync<Block>(url, body);
         }
+
+        public async Task<Block> Retrieve(string blockId)
+        {
+            if (string.IsNullOrWhiteSpace(blockId))
+            {
+                throw new ArgumentNullException(nameof(blockId));
+            }
+
+            var url = BlocksApiUrls.Retrieve(blockId);
+
+            return await _client.GetAsync<Block>(url);
+        }
     }
 }

Src/Notion.Client/Api/Blocks/IBlocksClient.cs

@@ -4,6 +4,13 @@ namespace Notion.Client
 {
     public interface IBlocksClient
     {
+        /// <summary>
+        /// Retrieves a Block object using the ID specified.
+        /// </summary>
+        /// <param name="blockId"></param>
+        /// <returns>Block</returns>
+        Task<Block> Retrieve(string blockId);
+
         Task<PaginatedList<Block>> RetrieveChildrenAsync(string blockId, BlocksRetrieveChildrenParameters parameters = null);
         Task<Block> AppendChildrenAsync(string blockId, BlocksAppendChildrenParameters parameters = null);
     }