Represents an exception thrown by the SDK.
A FacebookSDKException is thrown when something goes wrong. For example if an invalid signed request is sent to the Facebook\SignedRequest entity, it will throw an FacebookSDKException.
When an error response is returned from the Graph API, it will be thrown as a FacebookSDKException subtype called a Facebook\Exceptions\FacebookResponseException.
FacebookSDKException extends from the base \Exception class, so getCode() and getMessage() are available by default.