PHPDoc block updates & reverted observer fix

Author: subash-natarajan

app/code/Magento/Customer/Controller/Adminhtml/Group/Delete.php

@@ -1,6 +1,5 @@
 <?php
 /**
- *
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
@@ -9,6 +8,9 @@
 use Magento\Framework\App\Action\HttpPostActionInterface;
 use Magento\Framework\Exception\NoSuchEntityException;
 
+/**
+ * Class Delete
+ */
 class Delete extends \Magento\Customer\Controller\Adminhtml\Group implements HttpPostActionInterface
 {
     /**

app/code/Magento/Customer/Observer/AfterAddressSaveObserver.php

@@ -255,7 +255,7 @@ protected function addValidMessage($customerAddress, $validationResult)
                 : (string)__('You will not be charged tax.');
         }
 
-        $this->messageManager->addSuccessMessage(implode(' ', $message));
+        $this->messageManager->addSuccess(implode(' ', $message));
 
         return $this;
     }
@@ -280,7 +280,7 @@ protected function addInvalidMessage($customerAddress)
             $message[] = (string)__('You will be charged tax.');
         }
 
-        $this->messageManager->addErrorMessage(implode(' ', $message));
+        $this->messageManager->addError(implode(' ', $message));
 
         return $this;
     }
@@ -307,7 +307,7 @@ protected function addErrorMessage($customerAddress)
         $email = $this->scopeConfig->getValue('trans_email/ident_support/email', ScopeInterface::SCOPE_STORE);
         $message[] = (string)__('If you believe this is an error, please contact us at %1', $email);
 
-        $this->messageManager->addErrorMessage(implode(' ', $message));
+        $this->messageManager->addError(implode(' ', $message));
 
         return $this;
     }

app/code/Magento/Customer/Test/Unit/Observer/AfterAddressSaveObserverTest.php

@@ -575,7 +575,7 @@ public function testAfterAddressSaveNewGroup(
 
         if ($resultValidMessage) {
             $this->messageManager->expects($this->once())
-                ->method('addSuccessMessage')
+                ->method('addSuccess')
                 ->with($resultValidMessage)
                 ->willReturnSelf();
         }
@@ -585,7 +585,7 @@ public function testAfterAddressSaveNewGroup(
                 ->with($vatId)
                 ->willReturn($vatId);
             $this->messageManager->expects($this->once())
-                ->method('addErrorMessage')
+                ->method('addError')
                 ->with($resultInvalidMessage)
                 ->willReturnSelf();
         }
@@ -595,7 +595,7 @@ public function testAfterAddressSaveNewGroup(
                 ->with('trans_email/ident_support/email', ScopeInterface::SCOPE_STORE)
                 ->willReturn('admin@example.com');
             $this->messageManager->expects($this->once())
-                ->method('addErrorMessage')
+                ->method('addError')
                 ->with($resultErrorMessage)
                 ->willReturnSelf();
         }