# File lib/active_support/core_ext/module/delegation.rb, line 99
  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]}_"

    file, line = caller.first.split(':', 2)
    line = line.to_i

    methods.each do |method|
      on_nil =
        if options[:allow_nil]
          'return'
        else
          %(raise "#{prefix}#{method} delegated to #{to}.#{method}, but #{to} is nil: \#{self.inspect}")
        end

      module_eval("def \#{prefix}\#{method}(*args, &block)               # def customer_name(*args, &block)\n\#{to}.__send__(\#{method.inspect}, *args, &block)  #   client.__send__(:name, *args, &block)\nrescue NoMethodError                                # rescue NoMethodError\nif \#{to}.nil?                                     #   if client.nil?\n\#{on_nil}\nelse                                              #   else\nraise                                           #     raise\nend                                               #   end\nend                                                 # end\n", file, line)
    end
  end