Fix tests

tests/Monolog/Handler/NullHandlerTest.php

@@ -33,12 +33,12 @@ class NullHandlerTest extends TestCase
 
     public function testSerializeRestorePrivate()
     {
-        $handler = new NullHandler(Logger::WARNING);
-        self::assertFalse($handler->handle($this->getRecord(Logger::DEBUG)));
-        self::assertTrue($handler->handle($this->getRecord(Logger::WARNING)));
+        $handler = new NullHandler(Level::Warning);
+        self::assertFalse($handler->handle($this->getRecord(Level::Debug)));
+        self::assertTrue($handler->handle($this->getRecord(Level::Warning)));
 
         $handler = unserialize(serialize($handler));
-        self::assertFalse($handler->handle($this->getRecord(Logger::DEBUG)));
-        self::assertTrue($handler->handle($this->getRecord(Logger::WARNING)));
+        self::assertFalse($handler->handle($this->getRecord(Level::Debug)));
+        self::assertTrue($handler->handle($this->getRecord(Level::Warning)));
     }
 }