package aeronicamc.mods.mxtune.gui;

import net.minecraft.client.Minecraft;

public class Handler
{
    private static final Minecraft mc = Minecraft.getInstance();

    private Handler()
    {
        // NOP
    }

    public static void openTestScreen()
    {
        mc.tell(()->mc.setScreen(new TestScreen(null)));
    }
    public static void openGuiMultiInstChooser()
    {
        mc.tell(()->mc.setScreen(new GuiMultiInstChooser(null)));
    }
}

@@ -30,16 +30,61 @@
 e.gui;%0A%0A
+import aeronicamc.mods.mxtune.util.AntiNull;%0A
 import n
@@ -348,20 +348,16 @@
 tScreen(
-null
 )));%0A   
@@ -475,12 +475,34 @@
 ser(
-null
+AntiNull.nonNullInjected()
 )));

Stop IntelliJ null warnings for non-null allow parameters...