Does it imply too much complacent comfort that I, only a few minutes into WTF’s compelling production of A Streeetcar Named Desire, leaned back and said to myself, “This is it. They’re on track. I’m just going to follow this along.” The first bit of business between the Negro Woman and Eunice, vividly played by Crystal Lucas-Perry and Jennifer Engstrom, was magical, and it stayed that way throughout the entire production. The Williamstown Theatre Festival, under its new Artistic Director, Jenny Gersten, could not have gotten off to a better start: a great classic play in a great production. It was clearly intended to be a revisionist effort, with Sam Rockwell’s entirely un-Brando-like Stanley, and its claustrophobic set, crammed with the banal accoutrements of American life in the late 1940s. But after Omar Sangare’s treatment only a few months ago on the same stage, it seemed conventional, not to the detriment of either production.