Remove usage of Value Factory and optimize imports

Author: TomashKhamlai

app/code/Magento/CustomerGraphQl/Model/Resolver/Customer/Account/GenerateCustomerToken.php

@@ -7,14 +7,12 @@
 
 namespace Magento\CustomerGraphQl\Model\Resolver\Customer\Account;
 
-use Magento\Integration\Api\CustomerTokenServiceInterface;
+use Magento\Framework\Exception\AuthenticationException;
 use Magento\Framework\GraphQl\Config\Element\Field;
 use Magento\Framework\GraphQl\Exception\GraphQlAuthorizationException;
-use Magento\Framework\Exception\AuthenticationException;
-use Magento\Framework\GraphQl\Query\Resolver\Value;
-use Magento\Framework\GraphQl\Query\Resolver\ValueFactory;
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
+use Magento\Integration\Api\CustomerTokenServiceInterface;
 
 /**
  * Customers Token resolver, used for GraphQL request processing.
@@ -26,21 +24,14 @@ class GenerateCustomerToken implements ResolverInterface
      */
     private $customerTokenService;
 
-    /**
-     * @var ValueFactory
-     */
-    private $valueFactory;
-
     /**
      * @param CustomerTokenServiceInterface $customerTokenService
-     * @param ValueFactory $valueFactory
      */
     public function __construct(
-        CustomerTokenServiceInterface $customerTokenService,
-        ValueFactory $valueFactory
+        CustomerTokenServiceInterface $customerTokenService
+
     ) {
         $this->customerTokenService = $customerTokenService;
-        $this->valueFactory = $valueFactory;
     }
 
     /**
@@ -55,7 +46,7 @@ public function resolve(
     ) {
         try {
             $token = $this->customerTokenService->createCustomerAccessToken($args['email'], $args['password']);
-            return !empty($token) ? ['token' => $token] : '';
+            return ['token' => $token];
         } catch (AuthenticationException $e) {
             throw new GraphQlAuthorizationException(
                 __($e->getMessage())