# File lib/rspec/rails/mocks.rb, line 157
      def stub_model(model_class, stubs={})
        primary_key = model_class.primary_key.to_sym
        stubs = {primary_key => next_id}.merge(stubs)
        model_class.new.tap do |m|
          m.__send__("#{primary_key}=", stubs.delete(primary_key))
          m.extend ModelStubber
          m.stub(stubs)
          yield m if block_given?
        end
      end