[1.9] Change title text in custom large chest GUI

Hi!

This is a very simple question, but I couldn't find the answer to it anywhere. I know you can set the text on the title of normal chests in the TileEntity class like this:

public String getName()
    {
        return this.hasCustomName() ? this.customName : "container.spruceChest";
    }

But I can't figure out how to do this for the large chests.