UPDATE 3-White House budget official testifies in impeachment probe on Saturday

A White House budget official walked into a closed session of the U.S. House of Representatives impeachment inquiry of President Donald Trump on Saturday, where he testified about the holdup of military aid to Ukraine.Mark Sandy, a career official of the Office of Management and Budget, is the first person from OMB to testify before the inquiry after three political appointees defied congressional subpoenas to appear.Sandy complied with a subpoena issued to compel his testimony, an official work