An Extension is a Qi4j component that is NOT intended to be used by the client code directly.An extension in the sandbox is discouraged to be used for any purpose other than experimental and assisting in getting it to production quality. Users are requested to think carefully prior to use extensions from the sandbox.
The artifacts in the Sandbox are also never released, and not required to be operational at all times. The Continuous Integration system doesn't cover the sandbox, and the overall documentation and quality of components in the sandbox is poor.
