hiding_things_on_my_eigenclass.rb

10:21:48 $ irb
irb(main):001:0> module FooA
irb(main):002:1>   BAR = "bar"
irb(main):003:1> end
=> "bar"
irb(main):004:0> FooA::BAR
=> "bar"
irb(main):005:0> module FooB
irb(main):006:1>   class << self
irb(main):007:2>     BAR = "bar"
irb(main):008:2>   end
irb(main):009:1> end
=> "bar"
irb(main):010:0> FooB::BAR
NameError: uninitialized constant FooB::BAR
	from (irb):10
	from /Users/lucas/.rbenv/versions/2.1.2/bin/irb:11:in `<main>'