if (!isConnectorInfoSet(job))
throw new IOException("Connector info has not been set.");
try {
// if the instance isn't configured, it will complain here
String principal = getPrincipal(job);
AuthenticationToken token = getAuthenticationToken(job);
Connector c = getInstance(job).getConnector(principal, token);
if (!c.securityOperations().authenticateUser(principal, token))
throw new IOException("Unable to authenticate user");
} catch (AccumuloException e) {
throw new IOException(e);