{ "values": [[1511596680,3],[1511596740,2],[1511596800,0],[1511596860,6],[1511596920,0],[1511596980,0],[1511597040,0],[1511597100,0],[1511597160,0],[1511603220,0],[1511603280,0],[1511603340,0],[1511603400,0],[1511603460,0],[1511603520,0],[1511603580,0],[1511603640,0],[1511603700,0],[1511603760,0],[1511603820,0]]}

$contenttype = 'application/json';

$headers = array(
       'Content-Type: ' . $contenttype,
       'Content-Length: ' . strlen($post_string) /* this an empty string */
        );

/* dump of headers

Array
(
    [0] => Content-Type: application/json
    [1] => Content-Length: 0
)
*/

$ch = curl_init($url);

curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method); // this is get */
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
if (is_array($headers)
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
$output = curl_exec($ch); // this contains the crap at the start */