在Rspec中是否存在it_behaves_like的反转？

Question

是否有一些东西会影响到它的效果？#_ itesnt_behave_like＆＃39;或者＆＃39; group_will_fail_with（SomeError）＆＃39;？我在文档中看不到任何内容，但我觉得这是理想的功能。 E.g。

shared_examples_for "a foo doer for admin" do
  it "does this" do
   ...
  end

  it "does that" do
   ...
  end
end

context "when logged in as an admin" do
  let(:admin)   { FactoryGirl :admin }
  before(:each) { sign_in_as admin }

  it_behaves_like "a foo doer for admin"
end

context "when logged in as a user" do
  let(:user)    { FactoryGirl :user }
  before(:each) { sign_in_as user }

  # is there something like this?
  group_will_fail_with("a foo doer for admin", SomeError) / it_behaves_not_like "a foo maker" / etc.
end

如果这是反模式，或者我的想法有问题，那么所有的更正都会受到赞赏。