How to get the CRM ID of a related record through expression

[joebordes]

Unit test don't seem to agree with you:

https://github.com/tsolucio/coreBOSTests/blob/master/modules/com_vtiger_workflow/expression_functions/aggregationTest.php#L31:L37
https://github.com/tsolucio/coreBOSTests/blob/master/modules/com_vtiger_workflow/expression_functions/aggregationTest.php#L51:L61

Two things come to mind:
- the code actually works differently when executed in the unit test (I truly hope not)
- the omnipresent number formatting is getting in the way