def assert_have_selector(name, attributes = {}, &block)
      matcher = HaveSelector.new(name, attributes, &block)
      assert matcher.matches?(response_body), matcher.failure_message
    end
def assert_have_selector(name, attributes = {}, &block)
      matcher = HaveSelector.new(name, attributes, &block)
      assert matcher.matches?(response_body), matcher.failure_message
    end
Asserts that the body of the response contains
 the supplied selector