Say I call getRecordById for a product and the product comes successfully.

product = getRecordById("Products", id)

Then I want the Product Type element but let's say that this does not exist in 'product'. 

prodType = product.get("Product Type")

What is the value of prodType in this case? Is it null or an empty string? What would be the result of the check below? Would it throw an exception or return false?

prodType.contains("Test Type")