Error in TaskService

I create a Symfony2 project and Camunda. I use the Camunda SDK PHP API. I want to send a complete action to Camunda Task and the variables from my Symfony2 project. I write this code:

$data = array(‘variables’=>array(
‘accepted’ => array(
‘value’ => 1
‘cause’ => array(
‘value’ => ‘test’
$camundaAPI = new \org\camunda\php\sdk\Api(‘http://myserver/engine-rest’);
$taskDefinitionRequest = new \org\camunda\php\sdk\entity\request\TaskRequest();
$taskDefinitions = $camundaAPI->task->getTask(taskId);

I execute this code, an error message is displayed:
Catchable Fatal Error: Argument 1 passed to org\camunda\php\sdk\helper\CastHelper::cast() must be an instance of stdClass, array given, called in /projet/workflow-php-camunda/vendor/camunda/camunda-bpm-php-sdk/oop/main/service/TaskService.php on line 34 and defined

Can You help me ??