Get Stream by User not working

I’m using jQuery’s $.getJSON() method for fetching the data, which looks like this -

$.getJSON(“https://api.twitch.tv/kraken/streams/< user id >?client_id=< client id >”, function(json) {
console.log(json);
});

The output is following for any user id, whether the channel is offline or online -

{
“stream”: null,
“_links”: {
“self”: “https://api.twitch.tv/kraken/streams/79776140”,
“channel”: “https://api.twitch.tv/kraken/channels/79776140
}
}

which doesn’t comply to the response format in the documentation!