It is used in ContextR as well, and its
redefinition is simple, The functionality of method missing is 
one of the core ingredients of cleanly designed Ruby programs, it is still 
possible to extend it with context-dependent behaviour.

The following code will show the right usage.

    class MethodMissingExample
      def method_missing(*a)
        "base"
      end

      in_layer :one do
        def method_missing(*a, &b)
          "pre_one " + super
        end
      end
      in_layer :two do
        def method_missing(*a, &b)
          super + " post_two"
        end
      end
    end

    example do
      instance = MethodMissingExample.new
      result_of(instance.any_method) == "base"

      ContextR::with_layer :one do
        result_of(instance.any_method) == "pre_one base"
      end
      ContextR::with_layer :two do
        result_of(instance.any_method) == "base post_two"
      end

      ContextR::with_layer :one, :two do
        result_of(instance.any_method) == "pre_one base post_two"
      end
    end