function forestry_bees.Bee(bee_type,active_gene,inactive_gene)
    local itemstack = ItemStack({name = forestry_bees.bee_name(bee_type,active_gene)})
    itemstack:get_meta():set_string("active_gene",active_gene)
    itemstack:get_meta():set_string("inactive_gene",inactive_gene)
    return itemstack
end

function forestry_bees.bee_name(bee_type,active_gene)
    return "forestry_bees:"..active_gene.."_"..bee_type
end

function forestry_bees.stacks_in_inv(inv,listname)
  local stack_list = inv:get_list(listname)
  local result = 0
  for i = 1,#stack_list do
    if not stack_list[i]:is_empty() then
      result = result + 1
    end
  end
  return result
end