Hayden Christensen thought his ‘Star Wars’ role was so “unattainable” he asked for another part. The 42-year-old actor made his debut as Anakin Skywalker – who becomes Darth Vader – in 2002’s ‘Star Wars: Episode II – Attack of the Clones’, and he wasn’t convinced he’d get the job. He told Empire magazine: “I was 18, and I got a call from my agent saying that they were casting for Anakin Skywalker in ‘Star Wars’ and I thought, ‘Wow, how cool.’ “But it just seemed too big. And I remember asking my agent, ‘Is there maybe another role that they’re also casting right now that you can put me up for?…