How can I use this function? (check if chat is opened)

So I need to know if a player has his chat open, I found a function that returns true if the chat is opened, but I dont know how to use it. The function is:

func_146241_e || getChatOpen || Returns true if the chat GUI is open.

Also I found it on the deobfuscated minecraft code: 

private boolean getChatOpen() { return this.mc.currentScreen instanceof ChatScreen; }

It is part of the NewChatGui.java class, inside the screen folder, inside the gui folder.

Im using mc 1.16.5, specifically using cnpcs mod to create some good stuff. Thx in advance.