php – Laravel 4：Config get返回数组或null

$client_id  = Config::get('lightshire/laravel-paypal::client_id');

它返回的只是array(0){}

我的服务提供商

<?php
namespace LightshirePaypal;

use IlluminateSupportServiceProvider as IlluminateServiceProvider;

class PaypalServiceProvider extends IlluminateServiceProvider
{
    protected $defer = false;

    public function boot()
    {
        $this->package("lightshire/laravel-paypal");
        include app_path()."/routes.php";
    }

    public function register()
    {
        $this->app["paypal"] = $this->app->share(function($app)
        {

            return new Paypal;
        });
    }
    public function provides()
    {
        return array('paypal');
    }
}

我的Paypal.php

<?php
    namespace LightshirePaypal;

    require base_path()."/vendor/autoload.php";


    use App;
    use Config;


    class Paypal
    {
        private $creds = null;
        private $token = null;

        public function __construct()
        {
            // // $data = Paypal::launch();
            // $this->creds = $data["creds"];
            // $this->token = $data["token"];

        }



        public static function getTokenCreds()
        {



            $client_id  = Config::get('lightshire/laravel-paypal::client_id');
            $secret     = Config::get('laravel-paypal:secret');
            $mode       = Config::get('laravel-paypal:mode');
            $endPoint   = Config::get('laravel-paypal:endpoint');
;
            $headers    = array(
                    // 'Authorization' => 'Basic '.$encodedID,'Accept'            =>  'application/json','Accept-Language'   => 'en_US'
                ); 

            $params     = array(
                    'grant_type'    => 'client_credentials'
                ); 

            $url        = "https://api.sandbox.paypal.com/v1/oauth2/token";

            dd($client_id);

            $ch = curl_init();
            curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
            curl_setopt($ch,CURLOPT_HTTPAUTH,CURLAUTH_ANY);
            curl_setopt($ch,CURLOPT_USERPWD,$client_id.":".$secret);
            curl_setopt($ch,CURLOPT_URL,$url);
            curl_setopt($ch,CURLOPT_POST,true);
            curl_setopt($ch,CURLOPT_HEADER,CURLOPT_HTTPHEADER,$headers);
            curl_setopt($ch,CURLOPT_POSTFIELDS,$params);

            $response = curl_exec($ch);

            curl_close($ch);

            return $response;
        }
    }

知道为什么吗？