By Bill Esdaile DONCASTER is the setting for the final Group One of the British Flat season this weekend, the William Hill Futurity Stakes (2.40pm). In recent years this mile contest has had a real impact on the Classics the following season, with three of the last five winners – Auguste Rodin, Mac Swiney and Kameko – all going on to win Classics either in Britain or Ireland the following season. Whether this year’s race holds such a star is hard to ascertain and on paper it doesn’t look the strongest of renewals. If there is a horse in the line-up with the potential to be among the best of ne…