matchers.go
func HaveKeyWithValue(key interface{}, value interface{}) types.GomegaMatcher {
	return &matchers.HaveKeyWithValueMatcher{
		Key:   key,
		Value: value,
	}
}
func HaveKeyWithValue(key interface{}, value interface{}) types.GomegaMatcher {
	return &matchers.HaveKeyWithValueMatcher{
		Key:   key,
		Value: value,
	}
}
//HaveKeyWithValue succeeds if actual is a map with the passed in key and value.
//By default HaveKeyWithValue uses Equal() to perform the match, however a
//matcher can be passed in instead:
//    Expect(map[string]string{"Foo": "Bar", "BazFoo": "Duck"}).Should(HaveKeyWithValue("Foo", "Bar"))
//    Expect(map[string]string{"Foo": "Bar", "BazFoo": "Duck"}).Should(HaveKeyWithValue(MatchRegexp(`.+Foo$`), "Bar"))