getModuleScript
public ModuleScript getModuleScript(Context cx,
                                    java.lang.String moduleId,
                                    java.net.URI uri,
                                    java.net.URI base,
                                    Scriptable paths)
                             throws java.lang.Exception
Returns a module script. It should attempt to load the module script if it is not already
 available to it, or return an already loaded module script instance if it is available to it.
- Specified by:
- getModuleScriptin interface- ModuleScriptProvider
- Parameters:
- cx- current context. Can be used to compile module scripts.
- moduleId- the ID of the module. An implementation must only accept an absolute ID,
     starting with a term.
- uri- the URI of the module. If this is not null, resolution of- moduleId
     is bypassed and the script is directly loaded from- moduleUri
- base- the module path base URI from which- moduleUriwas derived.
- paths- the value of the require() function's "paths" attribute. If the require()
     function is sandboxed, it will be null, otherwise it will be a JavaScript Array object.
     It is up to the provider implementation whether and how it wants to honor the contents of
     the array.
- Returns:
- a module script representing the compiled code of the module. Null should be returned
     if the script could not found.
- Throws:
- java.lang.Exception- if there was an unrecoverable problem obtaining the script
- java.lang.IllegalArgumentException- if the module ID is syntactically not a valid absolute
     module identifier.