Ruby 2.0 refinements

refinements.rb

module TimeExtensions
  refine Fixnum do
    def minutes; self * 60; end
  end
end

class MyApp
  using TimeExtensions
  def initialize
    p 2.minutes
  end
end

p TimeExtensions.refinements # => {Fixnum=>#<Module:0xb7ef49a0>}
MyApp.new    # => 120
p 2.minutes  # => NoMethodError