+INVALID_TICKET = 'INVALID_TICKET'
+INVALID_SERVICE = 'INVALID_SERVICE'
+INVALID_REQUEST = 'INVALID_REQUEST'
+INTERNAL_ERROR = 'INTERNAL_ERROR'
+
+ERROR_MESSAGES = (
+ (INVALID_TICKET, u'The provided ticket is invalid.'),
+ (INVALID_SERVICE, u'Service is invalid'),
+ (INVALID_REQUEST, u'Not all required parameters were sent.'),
+ (INTERNAL_ERROR, u'An internal error occurred during ticket validation'),
+)
+
+