This file contains all functions and macros required for correct drawing of visual elements in Graphical Installer powered installers. This is a core file and it must not be edited manually! This file includes all required files – Modern UI 2 pages, NSIS core files, etc. All necessarry symbol and variables and a lot of othe stuff is defined within this file.

You can see a fragment of this file here:

Tip:
All Graphical Installer powered installers must include this file. Do not forget to define GRAPHICAL_INSTALLER_PROJECT_UID before including this file!

Example - how to include GraphicalInstaller_functions.nsh file into your script.