Remove useless class

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Add javadoc.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Added javadoc, remove useless classes, added some tests.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>