Insufficient documentation for the `sourceUrl` argument to the `JsRunScript` function

The documentation for `JsRunScript` function at https://github.com/microsoft/ChakraCore/wiki/JsRunScript doesn't really tell much about allowed values (including the null pointer) and their interpretation for the `sourceUrl` argument:

> sourceUrl: The location the script came from.

Scripts do not always come from "locations" as these uniform locations cannot be identified -- since one simply passes strings to `JsRunScript`, it makes no sense to mandate a location for such script.

I assumed the argument was optional and tried to pass `NULL` as value, but the function returned an error. What are my options? Am I supposed to cook up a bogus location to indicate no location condition? Like an empty string, for instance?