Deprecate the attributes and use headers.

pkg/gps/GpsMessage.php

@@ -24,6 +24,11 @@ class GpsMessage implements Message, \JsonSerializable
      */
     private $headers;
 
+    /**
+     * @var array
+     */
+    private $attributes = [];
+
     /**
      * @var bool
      */
@@ -34,11 +39,12 @@ class GpsMessage implements Message, \JsonSerializable
      */
     private $nativeMessage;
 
-    public function __construct(string $body = '', array $properties = [], array $headers = [])
+    public function __construct(string $body = '', array $properties = [], array $headers = [], array $attributes = [])
     {
         $this->body = $body;
         $this->properties = $properties;
         $this->headers = $headers;
+        $this->attributes = $attributes;
 
         $this->redelivered = false;
     }
@@ -80,7 +86,7 @@ public function setHeaders(array $headers): void
 
     public function getHeaders(): array
     {
-        return $this->headers;
+        return array_merge($this->attributes, $this->headers);
     }
 
     public function setHeader(string $name, $value): void
@@ -173,4 +179,20 @@ public function setNativeMessage(?GoogleMessage $message = null): void
     {
         $this->nativeMessage = $message;
     }
+
+    /**
+     * @deprecated This will be removed in the V1, use headers instead
+     */
+    public function setAttributes(array $attributes): void
+    {
+        $this->attributes = $attributes;
+    }
+
+    /**
+     * @deprecated This will be removed in the V1, use headers instead
+     */
+    public function getAttributes(): array
+    {
+        return $this->attributes;
+    }
 }