How do I use TVMLKit MediaItem loadCertificate

Could someone please post some code examples of how to use the MediaItem loadCertificate.


The documentation doesn't explain how to use it properly.


I understand that:


singleVideo.loadCertificate = function certificate(url, callback) { ... }



But what invokes this function? How is the url parameter set?


If my certificate is located at https://somedomain.com/mycertificate


how is this passed to the certificate() function?