Implemented the GET /users/{username}/collection/folders/{folder_id} endpoints for the Open API specification document in the library target.

Sources/DiscogsService/openapi.yaml

@@ -1064,7 +1064,7 @@ paths:
     get:
       tags:
         - User Collection
-      summary: Get collection folder of a user.
+      summary: Get all the collection folders of a user.
       description: |
         Retrieves a list of folders in a collection of a user. 
         
@@ -1104,7 +1104,7 @@ paths:
     post:
       tags:
         - User Collection
-      summary: Create a new collection folder.
+      summary: Create a new collection folder for a user.
       description: |
         Creates a new folder in the collection of a user.
 
@@ -1134,6 +1134,43 @@ paths:
                 $ref: '#/components/schemas/Folder'
         '403':
           $ref: '#/components/responses/NotAccessable'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '500':
+          $ref: '#/components/responses/InternalError'
+  /users/{username}/collection/folders/{folder_id}:
+    get:
+      tags:
+        - User Collection
+      summary: Get information about a collection folder of a user.
+      description: |
+        Retrieves metadata about a collection folder of a user.
+
+        In case the `folder_id` is not 0, then the endpoint requires authentication as the collection owner.
+      operationId: getUserCollectionFolder
+      parameters:
+        - $ref: '#/components/parameters/Username'
+        - $ref: '#/components/parameters/FolderId'
+      responses:
+        '200':
+          description: Successfully retrieved a specific collection folder of a user.
+          headers:
+            X-Discogs-RateLimit:
+              $ref: '#/components/headers/RateLimit'
+            X-Discogs-RateLimit-Used:
+              $ref: '#/components/headers/RateLimitUsed'
+            X-Discogs-RateLimit-Remaining:
+              $ref: '#/components/headers/RateLimitRemaining'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Folder'
+        '403':
+          $ref: '#/components/responses/NotAccessable'          
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '500':
+          $ref: '#/components/responses/InternalError'
         '500':
           $ref: '#/components/responses/InternalError'
 components:
@@ -1186,8 +1223,8 @@ components:
       required: true
   parameters:
     ArtistId:
-      name: artist_id
       description: An identifier of an artist.
+      name: artist_id
       in: path
       required: true
       schema:
@@ -1205,15 +1242,15 @@ components:
           - title
           - format
     Authorization:
-      name: Authorization
       description: A string to authenticate a user with a service by carrying credentials.
+      name: Authorization
       in: header
       required: true
       schema:
         type: string
     ContentType:
-      name: Content-Type
       description: A content type for a response.
+      name: Content-Type
       in: header
       required: true
       schema:
@@ -1236,6 +1273,14 @@ components:
       in: query
       schema:
         $ref: '#/components/schemas/Currency'
+    FolderId:
+      description: An identifier of a collection folder.
+      name: folder_id
+      in: path
+      required: true
+      schema:
+        type: integer
+      example: 0
     Format:
       description: A filter by format.
       name: format