The swipe method needs 5 parameters:
driver.swipe(start_x, start_y, end_x, end_y, duration)
you can also use:
elem.swipe(SwipeElementDirection.LEFT, 600)
But watch out, driver.swipe is going to be deprecated with java client 5.
Maybe you should go for TouchActions:
driver.performTouchAction(new IOSTouchAction(driver).press(elem)
.moveTo(0, elem.getLocation().getY())
.release());