How about passing a variable to this method that defaults to `example` but when raised from `with_temporary_scope` sets it to `context`, then it'd be slightly less confusing in that scenario?

```Ruby
"#{intro} was originally created in one example but has leaked into " +
"another context and can no longer be used. rspec-mocks' doubles are " +
"designed to only last for one context, and you need to create a new " +
"one in each context you wish to use it for."
```