gistfile1.rb

2.2.1 :014 > module MyModule
2.2.1 :015?>   class ::String
2.2.1 :016?>     def excite
2.2.1 :017?>       "i am bored".excite
2.2.1 :018?>       end
2.2.1 :019?>     end
2.2.1 :020?>   end
 => :excite 
2.2.1 :021 > "sup".excite
SystemStackError: stack level too deep
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
	from (irb):17:in `excite'
... 10032 levels...