Monkey patching

module Cucumber
  module Formatter
    class Html
      def initialize
      end
      def after_features
        puts "original after_features"
      end
    end
  end
end

orig = Cucumber::Formatter::Html.new
orig.after_features

module Cucumber
  module Formatter
    class Html
      def after_features
        puts "new after_features"
      end
    end
  end
end

new = Cucumber::Formatter::Html.new
new.after_features

# Adding method to instance
def new.after_features
  puts "added it to new"
end

new.after_features