Help with changing Shulker AI

I already know it isnt possible to open a menu with the ability to change AI but it was mentioned that you can change it with events. I essentially want to make it so that shulkers wont harm you when you are holding a particular item in your offhand. For example Shulkers wont attack you when you are holding a diamond in your offhand. I dont know if this is possible but any feedback would help. Thanks in advance!