Fix javadoc

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Fix #159

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Fix #165

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Fix #166

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