On the particular issue you report, however, the thing to notice is that the Automation.Library method exports only method names from the referenced library file. (See the Library section in JS for Automation release notes). (It doesn't export names which are bound to objects which are not themselves functions).
To obtain a reference to Dan's FileUtils module, you would need to call a method, at the top level of the library file, which returns a reference to the module you want to use.
If, for example we add such a method to the top of Dan's file:
We can then, from a client script, use the Automation.Library method like this:
