$uuid = 'eiv0u-arx5y-2c5ovx43zw90gvh';
$instance = $arv->{'pipeline_instances'}->{'get'}->execute('uuid' => $uuid);
print "ETag is ", $instance->{'etag'}, "\n";
$uuid = 'eiv0u-arx5y-2c5ovx43zw90gvh';
$instance = $arv->{'pipeline_instances'}->{'get'}->execute('uuid' => $uuid);
print "ETag is ", $instance->{'etag'}, "\n";