在同一控制器中调用其他函数？

我有这个控制器，以及 function read($q)返回错误 Call to undefined function sendRequest()

<?php


class InstagramController extends BaseController {


/*
|--------------------------------------------------------------------------
| Default Home Controller
|--------------------------------------------------------------------------
|
| You may wish to use controllers instead of, or in addition to, Closure
| based routes. That's great! Here is an example controller method to
| get you started. To route to this controller, just add the route:
|
|   Route::get('/', 'HomeController@showWelcome');
|
*/


public function read($q)
{
$client_id = 'ea7bee895ef34ed08eacad639f515897';


$uri = 'https://api.instagram.com/v1/tags/'.$q.'/media/recent?client_id='.$client_id;
return sendRequest($uri);
}


public function sendRequest($uri){
$curl = curl_init($uri);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
$response = curl_exec($curl);
curl_close($curl);
return $response;
}


}

我假设这是因为我以错误的方式引用了函数，但我找不到任何解释如何做到这一点。