minor #1425 Example missing `use` reference to Symfony's EventDispatcherInterface (shrikeh)

This PR was merged into the 2.0.x-dev branch.

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Example missing `use` reference to Symfony's EventDispatcherInterface

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4abe9de9 Example missing `use` reference to Symfony's EventDispatcherInterface

doc/providers.rst

@@ -131,6 +131,7 @@ Here is an example of such a provider::
     use Silex\Application;
     use Silex\Api\BootableProviderInterface;
     use Silex\Api\EventListenerProviderInterface;
+    use Symfony\Component\EventDispatcher\EventDispatcherInterface;
     use Symfony\Component\HttpKernel\KernelEvents;
     use Symfony\Component\HttpKernel\Event\FilterResponseEvent;