title: How do I unstub in rspec 3 without enabling the old syntax?
body: <p>I am upgrading from rspec 2 to rspec 3 and would like to use the new syntax and not enable the old syntax. But I have a few stubs that I set up in my top-level <code>before(:each)</code> block that I selectively <code>unstub</code> where I want the original implementation. </p>
  
  <p>Is there some equivalent way to remove a stub when I've defined it with the new <code>allow</code> syntax?</p>