Theme container calls callable binding on resolve

src/Gin/Foundation/Theme.php

@@ -30,11 +30,16 @@ public function bind($key, $value)
      * Resolve value from theme registry.
      *
      * @param  string $key
+     * @param  array $parameters
      *
      * @return mixed
      */
-    public function get($key)
+    public function get($key, $parameters = [])
     {
+        if (is_callable($callable = $this->registry[$key])) {
+            return call_user_func_array($callable, $parameters);
+        }
+
         return $this->registry[$key];
     }
 }

tests/Gin/Foundation/ThemeTest.php

@@ -17,12 +17,31 @@ public function it_return_same_instance_on_every_access()
     /**
      * @test
      */
-    public function test_binding_and_resolving_from_theme_container()
+    public function test_binding_and_resolving_value_from_theme_container()
     {
         $theme = Theme::getInstance();
 
         $theme->bind('key', 'value');
 
         $this->assertEquals(Theme::getInstance()->get('key'), 'value');
     }
+
+    /**
+     * @test
+     */
+    public function test_binding_and_resolving_closure_from_theme_container()
+    {
+        $theme = Theme::getInstance();
+
+        $theme->bind('key.without.parameters', function () {
+            return 'value';
+        });
+
+        $theme->bind('key.with.parameters', function ($param1, $param2) {
+            return $param1.','.$param2;
+        });
+
+        $this->assertEquals(Theme::getInstance()->get('key.without.parameters'), 'value');
+        $this->assertEquals(Theme::getInstance()->get('key.with.parameters', ['value1', 'value2']), 'value1,value2');
+    }
 }