FILE PHOTO: Berkshire Hathaway Chairman Warren Buffett walks through the exhibit hall as shareholders gather to hear from the billionaire investor at Berkshire Hathaway Inc's annual shareholder meeting in Omaha

FILE PHOTO: Berkshire Hathaway Chairman Warren Buffett walks through the exhibit hall as shareholders gather to hear from the billionaire investor at Berkshire Hathaway Inc’s annual shareholder meeting in Omaha