Footnotes

• Contributors RAD drafted the manuscript and it was revised and was edited by PK.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Disclaimer The views expressed in the submitted article are his or her own and not an official position of the institution or funder.

• Competing interests None declared.

• Provenance and peer review Commissioned; externally peer reviewed.