Added WARNING log

Author: ezimuel

src/Elasticsearch/Connections/Connection.php

@@ -283,6 +283,9 @@ private function wrapHandler(callable $handler): callable
                 } else {
                     $connection->markAlive();
 
+                    if (isset($response['headers']['Warning'])) {
+                        $this->logWarning($request, $response);
+                    }
                     if (isset($response['body']) === true) {
                         $response['body'] = stream_get_contents($response['body']);
                         $this->lastRequest['response']['body'] = $response['body'];
@@ -342,6 +345,11 @@ public function getHeaders(): array
         return $this->headers;
     }
 
+    public function logWarning(array $request, array $response): void
+    {
+        $this->log->warning('Deprecation', $response['headers']['Warning']);
+    }
+
     /**
      * Log a successful request
      *