LookupTable, ReST error management

[gianluca-valentini]

Hi,
I’m using LookupTable with HTTP ReST adapter. I’m using it in a pipeline rule.
It works fine but I’d like to understand how manage the ReST error response.

I mean, suppose that you use an IP address as key. On the ReST service, if the IP is not well formed, return a BAD_REQUEST json.
So How do you manage these scenarios?
Do you use Lookup Tables only when the response is safe?

Example:

let userData = lookup(“http-rest-lookup-table”, msg);
set_field(“name”, userData[“name”]);

How is possible to be sure that userData is not null and then set the field value?

Thanks
Gianluca