Who is the "possible double agent" mentioned in the article?
"One day after Trump gave Barr “full and complete” declassification authority to examine the origins of the Trump-Russia investigation in May 2019, the New York Times published a piece on this source “long-nurtured by the CIA” whom the outlet hinted was now in danger of being exposed in Russia — but he had already left the country. The source’s initial resistance to being pulled out reportedly led some to question whether he might be a double agent."