 of removed session should fail"});
                onComplete();
            }).catch(onFailure);
        }

        navigator.requestMediaKeySystemAccess(config.keysystem, [configuration] )
        .then(function(access) {
            return access.createMediaKeys();
        }).then(function(mediaKeys) {
            _mediaKeys = mediaKeys;
            return config.video.setMediaKeys(mediaKeys);
        }).then(function() {
            config.video.addEventListener('timeupdate', onTimeupdate, true);
     