[plt-scheme] Example of Inspectors and Modules?

Hi,
Does someone have a simple example of how to use parameter 
current-code-inspector for protection of modules? I dont grasp what section 
Inspectors and Modules of the MzScheme Language Manual is telling me. 
Specifically I want to make a module M that can be required by a user U. 
Module M requires some other modules J, K, L ... but I dont want U to be 
able to require the modules J, K, L ... because these provide side-effective 
procedures that should not be called by U directly. Does 
current-code-inspector help in this case? If so I would be very pleased with 
an example.
Jos Koot

((((lambda(x)((((((x x)x)x)x)x)x))
   (lambda(x)(lambda(y)(x(x y)))))
  (lambda(x)(write x)x))
 "greetings, Jos")