10 (D.C. Cir.1996); United States Trosper, 809 F.2d 110 , 111015th Cir. 1987); United States Vargas, 804 F.2d 1 , 163 st Cir. 1986); United States Suppa, 799 F.2d 115, 117 (3d Cir. 1116); United States Dominguez, 783 F.2d 702, 706 n. 7 (7th Cir 1986); United States Contreras, 76 F.2d 51, i (2d Cir

o the purpose of the proceeding." Id. 'That purpose includes neither a reprise of all the evidence presented before the grand jury, United States I Suppa, 799 F.2d 115, 119 (3d Cir. 1986), nor the right to confront non-testifying government witnesses, United States I Aceetturo, 783 F.2d 382, 388-89