Barack Obama makes a guest appearance in the new teaser trailer for Larry David’s upcoming sketch show Life, Larry and the Pursuit of Unhappiness . In the clip, the former U.S. president states: “I’ve sat across the table from some of the world’s most difficult leaders and wrestled with some of the globe’s most intractable problems. Nothing has prepared me for working with Larry David.” He continues: “I’m just a producer on the show, so I don’t have to deal with him day-to-day but still, it’s a lot.” Curb Your Enthusiasm creator David then appears and asks Obama if he can put him down as his medical emergency contact. “Because if they see your name, they’ll be more inclined to help,” quips David. The pair are working together on a new sketch comedy show , timed to coincide with the 250th anniversary of the United States of America. It is set to debut on HBO on June 27. New episodes will arrive weekly, with the season finale on August 8.…