FILE - The children of Berkshire Hathaway Chairman and CEO Warren Buffett, from left, Howard Buffett, Susie Buffett, and Peter Buffett, pose for a photo at the CenturyLink Center exhibit hall in Omaha, Neb., May 1, 2015. (AP Photo/Nati Harnik, File)

FILE - Peter Buffett, left, Warren Buffett, center, and Susie Buffett attend the world premiere screening of HBO's "Becoming Warren Buffett" at The Museum of Modern Art on Jan. 19, 2017 in New York. (Photo by Charles Sykes/Invision/AP, File)

In this undated photo, Philanthropist Howard Buffett, who will help distribute his dad Warren Buffett’s fortune after his death, takes pictures in Donetsk Oblast, Ukraine, during one of his many trips to Ukraine since Russia invaded that country. (Oles Maliarevych via AP)