Php setValidationGroup（）需要一个有效输入名称列表

我正试图通过cURL发送补丁请求，得到以下响应：

HTTP/1.1 400 Bad Request Server: nginx Date: Fri, 01 Apr 2016 09:16:03 GMT Content-Type: application/problem+json Content-Length: 198 Connection: keep-alive X-Powered-By: PHP/5.6.19 {"type":"http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html","title":"Internal Server Error","status":500,"detail":"setValidationGroup() expects a list of valid input names; \"\" was not found"}

我的代码：

sendData("2016-10-01", "2016-10-02", "1234");

function sendData($from, $to, $property){
    $data = array(
        "from" => $from,
        "to" => $to,
        "booking_id" => 3
    );
    $data = json_encode($data);
    echo $data . "<br>";
    $url = "https://api.urlhost.com/property/".$property."/avail";
    echo $url. "<br>";
    $headers = array('Authorization: Basic dGVhQGJsdW1lbnJpdmllcmEuOIT6Qmx1bQVucm17aAKyzTtyfw==','Content-Type: application/json-patch+json');
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($curl, CURLOPT_CUSTOMREQUEST, 'PATCH');
    curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_HEADER, true);

    $response = curl_exec($curl);
    echo ($response) . PHP_EOL;
    //print_r(curl_getinfo($ch));
    curl_close($curl);
}

但还是给了我这个错误。有什么建议可以解释为什么会发生这种情况吗

{"from":"2016-10-01","to":"2016-10-02","booking_id":3}
https://api.urlhost.com/property/1234/avail