Fix CS

Author: hlecorche

tests/App/Entity/Book.php

@@ -70,7 +70,7 @@ public function getTitle(): string
         return $this->title;
     }
 
-    public function setCategory(Category $category = null): self
+    public function setCategory(?Category $category = null): self
     {
         $this->category = $category;
 

tests/App/Entity/Sale.php

@@ -31,7 +31,7 @@ class Sale
     #[ORM\Column(type: 'integer')]
     protected $countSales;
 
-    public function setBook(Book $book = null): self
+    public function setBook(?Book $book = null): self
     {
         $this->book = $book;