PARK CITY, Utah (AP) — The normally private Taylor Swift has premiered a revealingly intimate documentary at the Sundance Film Festival. In it, the pop star discloses a past eating disorder, chronicles her inner battle over speaking out about politics and says her 2017 sexual assault court case was a dramatic turning point in her life. “Miss Americana” is a Netflix documentary directed by Lana Wilson, and it was one the most feverishly awaited film in this year’s Sundance program. Its premiere was a predictably frenzied scene. Outside the theater in Park City, Utah, dozens of Swift fans sang in unison. The film will debut Jan. 31 on Netflix.