In an aggressive attempt to promote its June 27 outdoor festival at Flushing Meadows, the Big3 — a three-on-three professional basketball league — appeared to brand Dolan as having racial animus in a full-page ad that ran in Friday’s Post. The Big3 advertisement contains, at the top, a quote from Dolan’s chief antagonist, Charles Oakley, stating, “It’s a plantation over there.’’