Cache container for IoC/DI integration

@UsingSpring (applies to Pico and Guice, I would assume) versus the use of Spring Test (@ContextConfiguration) does not cache the container and thus recreates it on every run.
Use of @ContextConfiguration caches the container (with a key made up of the location String array).
You can find this code in Spring Test in the TestContext class in the getApplicationContext method.

http://grepcode.com/file/repo1.maven.org/maven2/org.springframework/spring-test/3.0.2.RELEASE/org/springframework/test/context/TestContext.java

Enhancement would be to add a method to all the UsingXYZ annotations related to containers to cache the containers (always based on locations).