instrumentation.rb

    def override_class_method(klass, meth)
      # FIXME: This is somehow ugly. We should reduce the amount of
      # `evaled` code.
      str = " class << #{klass}

      original = '#{meth}'.to_sym
      saved_meth_name = '#{get_saved_method_name(meth)}'.to_sym
      new_method      = '#{meth}_modified'.to_sym

      alias_method saved_meth_name, original

      p = Instrumentation.define_callback_method(original, saved_meth_name,
                                                 #{klass})
      define_method(new_method, p)

      private new_method

      method_kind = nil
      case
      when public_method_defined?(original)
        method_kind = :public
      when protected_method_defined?(original)
        method_kind = :protected
      when private_method_defined?(original)
        method_kind = :private
      end
      alias_method original, new_method
      send(method_kind, original)
      private saved_meth_name
      end "
      eval str
    end