Missing ArrayAccess import

Author: jtreminio

modules/openapi-generator/src/main/resources/php/ObjectSerializer.mustache

@@ -19,6 +19,7 @@
 
 namespace {{invokerPackage}};
 
+use ArrayAccess;
 use GuzzleHttp\Psr7\Utils;
 use {{modelPackage}}\ModelInterface;
 

samples/client/petstore/php/OpenAPIClient-php/lib/ObjectSerializer.php

@@ -28,6 +28,7 @@
 
 namespace OpenAPI\Client;
 
+use ArrayAccess;
 use GuzzleHttp\Psr7\Utils;
 use OpenAPI\Client\Model\ModelInterface;
 

samples/client/petstore/php/psr-18/lib/ObjectSerializer.php

@@ -28,6 +28,7 @@
 
 namespace OpenAPI\Client;
 
+use ArrayAccess;
 use GuzzleHttp\Psr7\Utils;
 use OpenAPI\Client\Model\ModelInterface;