Extensions/Common/lib/vsts-task-lib/task.js
function getEndpointUrl(id, optional) {
    var urlval = getVariable('ENDPOINT_URL_' + id);
    debug(id + '=' + urlval);
    if (!optional && !urlval) {
        _writeError('Endpoint not present: ' + id);
        exit(1);
    }
    return urlval;
}
function getEndpointUrl(id, optional) {
    var urlval = getVariable('ENDPOINT_URL_' + id);
    debug(id + '=' + urlval);
    if (!optional && !urlval) {
        _writeError('Endpoint not present: ' + id);
        exit(1);
    }
    return urlval;
}
----------------------------------------------------- Endpoint Helpers -----------------------------------------------------