我正尝试使用STEPCONCURRENCYLEVEL作为新参数启动AWS EMR集群（发行标签-5.28.0），但是它使用默认值1，有人可以帮帮我。

这是我要添加的runjobflow的骨架。

    $client->runJobFlow([
        'Applications' => [

        ],'Configurations' => [

        ],'Instances' => [ 
        ],'JobFlowRole' => '','LogUri' => '','Name' => $cluster_name,// REQUIRED
        'ReleaseLabel' => $release_label,'StepConcurrencyLevel' => 10,'ServiceRole' => 'EMR_DefaultRole','VisibleToAllUsers' => true,]);