Example of ruby 2.1 refinements and their glory. Use with caution -- They are kind of code stinkies.

refinement.rb

module Refinement
  refine String do
    def reverse
      self[0..1]
    end
  end

end

class Boom
  using Refinement

  def bar
    "abc123".reverse
  end
end


puts Boom.new.bar  #=> "ab"
puts "abc123".reverse #=> "321cba"