Method setTagCompound

src/main/java/net/minecraft/item/ItemStack.java:577–580

Assigns a NBTTagCompound to the ItemStack, minecraft validates that only non-stackable items can have it.

(NBTTagCompound nbt)

     * Assigns a NBTTagCompound to the ItemStack, minecraft validates that only non-stackable items can have it.
     */
    public void setTagCompound(NBTTagCompound nbt)
    {
        this.stackTagCompound = nbt;
    }

    /**
     * returns the display name of the itemstack