fix ProphecyTrait in AbstractFilter to use it with each filter

src/Bundle/ChillMainBundle/Test/Export/AbstractFilterTest.php

@@ -13,6 +13,7 @@ namespace Chill\MainBundle\Test\Export;
 
 use Doctrine\ORM\QueryBuilder;
 use Exception;
+use Prophecy\PhpUnit\ProphecyTrait;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
 
 use function count;
@@ -27,14 +28,16 @@ use function is_string;
  */
 abstract class AbstractFilterTest extends KernelTestCase
 {
+    use ProphecyTrait;
+
     /**
      * @var \Prophecy\Prophet
      */
-    protected $prophet;
+    private $prophet;
 
     protected function setUp(): void
     {
-        $this->prepareProphet();
+        $$this->prophet = $this->getProphet();
     }
 
     public function dataProviderAlterQuery()