#---
# Excerpted from "The ThoughtWorks Anthology",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material, 
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose. 
# Visit http://www.pragmaticprogrammer.com/titles/twa for more book information.
#---

config = Configuration.new
config.add_item(Item.new(:secure_air_vent))

config.add_item(Item.new(:acid_bath))
config[:acid_bath].add_usage(Electricity.new(12))
acid = Acid.new
config[:acid_bath].add_usage(acid)
acid.type = :hcl
acid.grade = 5

config.add_item(Item.new(:camera))
config[:camera].add_usage(Electricity.new(1))

config.add_item(Item.new(:small_power_plant))
config[:small_power_plant].add_provision(Electricity.new(11))
config[:small_power_plant].add_dependency(config[:secure_air_vent])


return config