About the Authors

Valerio Capraro

V.Capraro@soton.ac.uk

Affiliation Department of Mathematics, University of Southampton, Southampton, United Kingdom

Competing Interests

The author has declared that no competing interests exist.

Author Contributions

I am the only author, so, I did everything! The manuscript do not contain any experiment, I would say only “wrote the manuscript”. Wrote the paper: VC.