400 Bad Request'); define( 'ERROR_401', '401 Unauthorized'); define( 'ERROR_403', '403 Forbidden'); define( 'ERROR_404', '404 Not Found'); define( 'ERROR_405', '405 Method Not Allowed'); define( 'ERROR_408', '408 Request Timeout'); define( 'ERROR_409', '409 Conflict'); define( 'ERROR_410', '410 Gone'); define( 'ERROR_415', '415 Unsupported Media Type'); define( 'ERROR_429', '429 Too Many Requests'); define( 'ERROR_500', '500 Internal Server Error'); define( 'ERROR_501', '501 Not Implemented'); define( 'ERROR_502', '502 Bad Gateway'); define( 'ERROR_503', '503 Service Unavailable'); define( 'ERROR_504', '504 Gateway Timeout'); define( 'ERROR_default', 'An Error Occurred');