VS don't stop localDB Instance

Hey,
If I get it correct, the automatic instance of localDB should start when I try to access localDB. So, if I try to connect to (localdb)/V11.0 from VS, it should create a instance, right ? But it should also close the instance once VS have finish with the connection, no ? Because, when I close my project, the instance is still running. I have to close manually from the command line (sqllocaldb stop V11.0). 
So, am I doing something wrong, or is it the correct behavior. And if is the correct behavior, is there a way to force the instance to stop once the application using is close ?

Thank you,
David
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