method_missing

# File activerecord/lib/active_record/associations/association_proxy.rb, line 208
        def method_missing(method, *args)
          if load_target
            unless @target.respond_to?(method)
              message = "undefined method `#{method.to_s}' for \"#{@target}\":#{@target.class.to_s}"
              raise NoMethodError, message
            end

            if block_given?
              @target.send(method, *args)  { |*block_args| yield(*block_args) }
            else
              @target.send(method, *args)
            end
          end
        end