refactor(controller): inherit from mixin

Author: jaredcnance

src/JsonApiDotNetCore/Controllers/JsonApiController.cs

@@ -3,7 +3,6 @@
 using System.Threading.Tasks;
 using JsonApiDotNetCore.Data;
 using JsonApiDotNetCore.Extensions;
-using JsonApiDotNetCore.Internal.Query;
 using JsonApiDotNetCore.Models;
 using JsonApiDotNetCore.Services;
 using Microsoft.AspNetCore.Mvc;
@@ -25,7 +24,7 @@ public JsonApiController(
     }
 
     public class JsonApiController<T, TId> 
-    : Controller where T : class, IIdentifiable<TId>
+    : JsonApiControllerMixin where T : class, IIdentifiable<TId>
     {
         private readonly IEntityRepository<T, TId> _entities;
         private readonly IJsonApiContext _jsonApiContext;
@@ -189,10 +188,5 @@ private IQueryable<T> IncludeRelationships(IQueryable<T> entities, List<string>
 
             return entities;
         }
-
-        protected IActionResult UnprocessableEntity()
-        {
-            return new StatusCodeResult(422);
-        }
     }
 }

src/JsonApiDotNetCore/Controllers/JsonApiControllerMixin.cs

@@ -0,0 +1,15 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace JsonApiDotNetCore.Controllers
+{
+    public class JsonApiControllerMixin : Controller
+    {
+        public JsonApiControllerMixin()
+        { }
+
+        protected IActionResult UnprocessableEntity()
+        {
+            return new StatusCodeResult(422);
+        }
+    }
+}