def to_ruby
      ruby = ['#!/usr/bin/env ruby']
      ruby << "$: << '#{File.expand_path('..', File.dirname(__FILE__))}'"
      ruby << 'require "aruba-doubles"'
      ruby << 'ArubaDoubles::Double.run do'
      @outputs.each_pair { |argv,output| ruby << "  on #{argv.inspect}, #{output.inspect}" }
      ruby << 'end'
      ruby.join("\n")
    end
def to_ruby
      ruby = ['#!/usr/bin/env ruby']
      ruby << "$: << '#{File.expand_path('..', File.dirname(__FILE__))}'"
      ruby << 'require "aruba-doubles"'
      ruby << 'ArubaDoubles::Double.run do'
      @outputs.each_pair { |argv,output| ruby << "  on #{argv.inspect}, #{output.inspect}" }
      ruby << 'end'
      ruby.join("\n")
    end
Export the double to executable Ruby code.

 @return [String] serialized double