it works!
@Override
public void initializeClient(java.util.function.Consumer<net.minecraftforge.client.IItemRenderProperties> consumer)
{
consumer.accept(new IItemRenderProperties()
{
@Override
public <A extends HumanoidModel<?>> A getArmorModel(LivingEntity entityLiving, ItemStack itemStack, EquipmentSlot armorSlot, A _default)
{
return KnightlyArmory.PROXY instanceof ClientProxy ? ((ClientProxy) KnightlyArmory.PROXY).getKnightModel(armorSlot) : null;
}
});
}