delegate (Module)

    # File lib/active_support/core_ext/module/delegation.rb, line 75
      def delegate(*methods)
        options = methods.pop
        unless options.is_a?(Hash) && to = options[:to]
          raise ArgumentError, "Delegation needs a target. Supply an options hash with a :to key as the last argument (e.g. delegate :hello, :to => :greeter)."
        end

        if options[:prefix] == true && options[:to].to_s =~ /^[^a-z_]/
          raise ArgumentError, "Can only automatically set the delegation prefix when delegating to a method."
        end

        prefix = options[:prefix] && "#{options[:prefix] == true ? to : options[:prefix]}_"

        methods.each do |method|
          module_eval("def \#{prefix}\#{method}(*args, &block)\n\#{to}.__send__(\#{method.inspect}, *args, &block)\nend\n", "(__DELEGATION__)", 1)
        end
      end