Exposes [ExampleGroup](ExampleGroup)-level methods to a module, so you can include that module in an [ExampleGroup](ExampleGroup).

@example

    module LoggedInAsAdmin
      extend RSpec::Core::SharedContext
      before(:each) do
        log_in_as :admin
      end
    end

    describe "admin section" do
      include LoggedInAsAdmin
      # ...
    end