1) ForgeHook.java

    /**
     * This method comprises the logic of {@link CrossbowItem#hasAmmo(LivingEntity, ItemStack)} & {@link CrossbowItem#func_220023_a(LivingEntity, ItemStack, ItemStack, boolean, boolean)}
     * Those two methods are being deprecated in favor of this hook method that in-lines the code.
     * @param pair The provided Pair of Ammo and Ammo Consumer.
     * @param shootable The shootable itemstack.
     * @param shooter The shooter.
     * @return returns a boolean if it succeeds in charging the crossbow.
     */
    public static boolean handleCrossbowCharging(Pair<ItemStack, Consumer<ItemStack>> pair, ItemStack shootable, LivingEntity shooter)
    {
        int i = EnchantmentHelper.getEnchantmentLevel(Enchantments.MULTISHOT, shootable);
        int j = i == 0 ? 1 : 3;
        boolean isCreative = shooter instanceof PlayerEntity && ((PlayerEntity)shooter).abilities.isCreativeMode;
        ItemStack itemstack = pair.getKey();
        ItemStack stackCopy = itemstack.copy();
        for(int k = 0; k < j; ++k)
        {
            if (k > 0)
                itemstack = stackCopy.copy();

            if (itemstack.isEmpty() && isCreative)
            {
                itemstack = new ItemStack(Items.ARROW);
                stackCopy = itemstack.copy();
            }

            boolean addedAmmo = false;

            if (!itemstack.isEmpty())
            {
                boolean notCreativeAndIsArrow = isCreative && itemstack.getItem() instanceof ArrowItem;
                ItemStack itemstack2;
                if (!notCreativeAndIsArrow && !isCreative && (k > 0))
                {
                    itemstack2 = itemstack.split(1);
                } else
                {
                    itemstack2 = itemstack;
                }
                pair.getValue().accept(itemstack);
                CrossbowItem.addChargedProjectile(shootable, itemstack2);
                addedAmmo = true;
            }
            if (!addedAmmo)
                return false;
        }
        return true;
    }

2) Crossbow Methods it's Replacing.java

   /**@deprecated Forge: This method has been inlined to get control over the ammo consumption chain, Use {@link net.minecraftforge.common.ForgeHooks#handleCrossbowCharging(org.apache.commons.lang3.tuple.Pair, ItemStack, LivingEntity)}*/
   @Deprecated
   private static boolean hasAmmo(LivingEntity entityIn, ItemStack stack) {
      int i = EnchantmentHelper.getEnchantmentLevel(Enchantments.MULTISHOT, stack);
      int j = i == 0 ? 1 : 3;
      boolean flag = entityIn instanceof PlayerEntity && ((PlayerEntity)entityIn).abilities.isCreativeMode;
      ItemStack itemstack = entityIn.findAmmo(stack);
      ItemStack itemstack1 = itemstack.copy();

      for(int k = 0; k < j; ++k) {
         if (k > 0) {
            itemstack = itemstack1.copy();
         }

         if (itemstack.isEmpty() && flag) {
            itemstack = new ItemStack(Items.ARROW);
            itemstack1 = itemstack.copy();
         }

         if (!func_220023_a(entityIn, stack, itemstack, k > 0, flag)) {
            return false;
         }
      }

      return true;
   }

   /**@deprecated Forge: This method has been inlined to get control over the ammo consumption chain, Use {@link net.minecraftforge.common.ForgeHooks#handleCrossbowCharging(org.apache.commons.lang3.tuple.Pair, ItemStack, LivingEntity)}*/
   @Deprecated
   private static boolean func_220023_a(LivingEntity p_220023_0_, ItemStack p_220023_1_, ItemStack p_220023_2_, boolean p_220023_3_, boolean p_220023_4_) {
      if (p_220023_2_.isEmpty()) {
         return false;
      } else {
         boolean flag = p_220023_4_ && p_220023_2_.getItem() instanceof ArrowItem;
         ItemStack itemstack;
         if (!flag && !p_220023_4_ && !p_220023_3_) {
            itemstack = p_220023_2_.split(1);
            if (p_220023_2_.isEmpty() && p_220023_0_ instanceof PlayerEntity) {
               ((PlayerEntity)p_220023_0_).inventory.deleteStack(p_220023_2_);
            }
         } else {
            itemstack = p_220023_2_.copy();
         }

         addChargedProjectile(p_220023_1_, itemstack);
         return true;
      }
   }

3) The event providing the ammo from an EnderChest.java

    @SubscribeEvent
    public static void onPlayerFindAmmo(LivingFindAmmoEvent event)
    {
        if (!ENABLE) return;
        if (event.getEntityLiving() instanceof PlayerEntity)
        {
            LOGGER.info("The LivingFindAmmoEvent has been called!");
            LOGGER.info("Firing Player targeted code!");
            PlayerEntity player = (PlayerEntity) event.getEntityLiving();
            LOGGER.info("Starting search of player Ender Chest for Ammo");
            EnderChestInventory inventory = player.getInventoryEnderChest();
            ItemStack ammo = ItemStack.EMPTY;
            int slot = 0;
            for (int i = 0; i < inventory.getSizeInventory() && ammo.isEmpty(); i++)
            {
                ItemStack stack = inventory.getStackInSlot(i);
                if (event.getAmmoPredicate().test(stack))
                {
                    LOGGER.info("Found valid ammo in player Ender Chest");
                    ammo = stack;
                    slot = i;
                    break;
                }
            }
            if (!ammo.isEmpty())
            {
                LOGGER.info("Set found ammo to Event");
                int finalSlot = slot;
                event.setAmmo(ammo, stack -> {
                    stack.shrink(1);
                    if (stack.isEmpty()) inventory.removeStackFromSlot(finalSlot);
                });
            }
        } else
        {
            event.setAmmo(new ItemStack(Items.SPECTRAL_ARROW), stack -> {});
        }
    }