How to pass null to RESTful object

As I observe, if I pass null value to a variable in test object, Katalon will ignore it. For example:

def loginAPI = new LoginAPI('abc', 'xyz', null)

will print {"userName":abc,"password":xyz,"companyId":${company}} instead of {"userName":"abc","password":"xyz","companyId":null}

Do you guys have anyway to bypass this?

I am also looking for an answer to this. So far, I do not seem to be able to use global or local variables as null types and have the variables actually replaced by a null value in the request. It shows as it does in the original post, as ${variableName} instead of null.

I was able to create a separate Request Object, in which I hardcoded null in the place where the variable would go and that worked. But it seems that duplicating a request object simply to replace a variable with a null value should not be necessary. There should be a way to pass a null value to a variable in a request.