add distinct format method for hal schema factory

Author: arnedesmedt

src/Hal/JsonSchema/SchemaFactory.php

@@ -50,9 +50,7 @@ public function __construct(SchemaFactoryInterface $schemaFactory)
     {
         $this->schemaFactory = $schemaFactory;
 
-        if (method_exists($schemaFactory, 'addDistinctFormat')) {
-            $schemaFactory->addDistinctFormat('jsonhal');
-        }
+        $this->addDistinctFormat('jsonhal');
     }
 
     /**
@@ -129,4 +127,11 @@ public function buildSchema(string $className, string $format = 'jsonhal', strin
 
         return $schema;
     }
+
+    public function addDistinctFormat(string $format): void
+    {
+        if (method_exists($this->schemaFactory, 'addDistinctFormat')) {
+            $this->schemaFactory->addDistinctFormat($format);
+        }
+    }
 }