php - マージ試行中の Bitbucket API 不正なリクエスト

Question

これは私のコードです:

$url = "https://bitbucket.org/api/2.0/repositories/***/***/pullrequests/35/merge";

$curl1 = curl_init();   

curl_setopt($curl1, CURLOPT_HTTPAUTH, CURLAUTH_BASIC ); 
curl_setopt($curl1, CURLOPT_USERPWD, "***:***");
curl_setopt($curl1, CURLOPT_HEADER, true); 
curl_setopt($curl1, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
curl_setopt($curl1, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl1, CURLOPT_URL, $url);
curl_setopt($curl1, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl1, CURLOPT_POST, true);

echo curl_exec($curl1);

それが応答です：

HTTP/1.1 400 BAD REQUEST Server: nginx/1.5.10 Date: Wed, 04 Mar 2015 06:03:15 GMT Content-Type: text/plain Content-Length: 11 Connection: keep-alive X-Served-By: app19 X-Render-Time: 0.0410010814667 Content-Language: de X-Static-Version: 572a80470390 Vary: Authorization, Accept-Language, Cookie X-Version: 1d224fb664b6 ETag: "825644f747baab2c00e420dbbc39e4b3" X-Request-Count: 27 X-Frame-Options: SAMEORIGIN Bad Request

これが機能しないのはなぜですか？(安全上の理由から、一部の情報を *** に置き換えました)