A PHP Error was encountered

Severity: Notice

Message: Use of undefined constant REST_URL - assumed 'REST_URL'

Filename: controllers/Learning_map.php

Line Number: 88

Backtrace:

File: /var/www/html/application/controllers/Learning_map.php
Line: 88
Function: _error_handler

File: /var/www/html/application/controllers/Learning_map.php
Line: 71
Function: curl_get

File: /var/www/html/application/controllers/Learning_map.php
Line: 36
Function: getAreaList

File: /var/www/html/index.php
Line: 292
Function: require_once