Replace get() with HttpClient In IssueCategory API

src/Redmine/Api/IssueCategory.php

@@ -7,6 +7,8 @@
 use Redmine\Exception\MissingParameterException;
 use Redmine\Exception\SerializerException;
 use Redmine\Exception\UnexpectedResponseException;
+use Redmine\Http\HttpFactory;
+use Redmine\Serializer\JsonSerializer;
 use Redmine\Serializer\PathSerializer;
 use Redmine\Serializer\XmlSerializer;
 
@@ -127,11 +129,26 @@ public function getIdByName($project, $name)
      *
      * @param int $id the issue category id
      *
-     * @return array information about the category
+     * @return array|false|string information about the category as array or false|string on error
      */
     public function show($id)
     {
-        return $this->get('/issue_categories/' . urlencode(strval($id)) . '.json');
+        $this->lastResponse = $this->getHttpClient()->request(HttpFactory::makeJsonRequest(
+            'GET',
+            '/issue_categories/' . urlencode(strval($id)) . '.json',
+        ));
+
+        $body = $this->lastResponse->getContent();
+
+        if ('' === $body) {
+            return false;
+        }
+
+        try {
+            return JsonSerializer::createFromString($body)->getNormalized();
+        } catch (SerializerException $e) {
+            return 'Error decoding body as JSON: ' . $e->getPrevious()->getMessage();
+        }
     }
 
     /**