如何从youtube v3中读取响应错误

I make a call to get my response and info , and then print it to view all is ok.

$data = file_get_contents( [CALL TO API]  );
$data = json_decode($data, true);
print("<pre>".print_r($data,true)."</pre>");

If the call is good, I will get my result no problem. but while testing, I need to know when it fails and why.

In the online test demo area, I will get this if it fail's.

{
 "error": {
  "errors": [
   {
    "domain": "youtube.subscription",
    "reason": "subscriptionForbidden",
    "message": "The requester is not allowed to access the requested subscriptions."
   }
  ],
  "code": 403,
  "message": "The requester is not allowed to access the requested subscriptions."
 }
}

But I only get a plank page.
So I then decided to look at my return header with

var_dump(headers_list());
var_dump(http_response_code());

This gives me

array(1) { [0]=> string(23) "X-Powered-By: PHP/5.4.7" }
int(200)

As you see, it is giving me a "200" OK header, but not much else. So how can I see what the youtube DEMO page shows me?
This would also be helpful later on for error checking when my site is finished.

$data = file_get_contents([CALL TO API]);
print_r($data); // Will print the response HTTP body
print_r($http_response_header); // Will print the response HTTP headers