Updated the unit tests #18162

Author: dmytro-ch

app/code/Magento/Customer/Test/Unit/Controller/Adminhtml/Index/InlineEditTest.php

@@ -6,6 +6,7 @@
 namespace Magento\Customer\Test\Unit\Controller\Adminhtml\Index;
 
 use Magento\Customer\Model\EmailNotificationInterface;
+use Magento\Framework\Message\MessageInterface;
 
 /**
  * @SuppressWarnings(PHPMD.TooManyFields)
@@ -242,10 +243,11 @@ protected function prepareMocksForErrorMessagesProcessing()
             ->method('getMessages')
             ->willReturn($this->messageCollection);
         $this->messageCollection->expects($this->once())
-            ->method('getItems')
+            ->method('getErrors')
             ->willReturn([$this->message]);
         $this->messageCollection->expects($this->once())
-            ->method('getCount')
+            ->method('getCountByType')
+            ->with(MessageInterface::TYPE_ERROR)
             ->willReturn(1);
         $this->message->expects($this->once())
             ->method('getText')