Fatal error: Cannot redeclare class OAuthSignatureMethod_HMAC_SHA1 in twitteroauth/OAuth.php on line 120 in laravel

Fatal error: Cannot redeclare class OAuthSignatureMethod_HMAC_SHA1 in twitteroauth/OAuth.php on line 120 

 Or 

 Cannot use Abraham Williams Twitter library in Laravel 4

Follow the steps:

 

Open OAuth.php

Remove this condition

if (!class_exists('OAuthException')) { class OAuthException extends Exception { // pass } }