Meng Wanzhou, chief financial officer of Huawei Technologies Co., leaves her home to attend Supreme Court for an extradition hearing in Vancouver, British Columbia, Canada, on Thursday, Jan. 23, 2020. At issue in a legal battle that has severely strained Canada-China relations is whether the U.S. extradition request meets the crucial test of double criminality: Would Meng's alleged crime have also been a crime in Canada? Photographer: Darryl Dyck/Bloomberg via Getty Images