Is it possible load in trasparent way for the user a cross reference file declaration in xtext web editor?

I'm building an integration of text editors in web applications using Xtext. I chose ace as editor, following following this documentation https://www.eclipse.org/Xtext/documentation/330_web_support.html. Is it possible to hide or load a cross reference declaration file in a transparent way for the user?

The actual editor shows:

Integers: int a, int b, int sum //cross reference declaration loaded from file

sum = s + a;

I want only the second line in the editor without obtain reference error.