By Amlan Chakraborty June 12 (Reuters) - New Zealand stalwart Kane Williamson quit international cricket on Friday, ending a stellar 16-year career marked by numerous accolades and by captaining his side to the title in the inaugural World Test Championship in 2021. Williamson's departure also suggests the sun is finally setting for batting's modern "Fab Four" of India's Virat Kohli, England's Joe Root, Australia's Steve Smith and Williamson himself.