quotation marks omitted). The defense bears the burden of satisfying the following three-part test: First, the district court must find that the government, through its own overreaching, has forced the witness to invoke the Fifth Amendment or, that the government has engaged in discriminatory use of grants of immunity to gain a tactical advantage; second, the witness’ testimony must be material, exculpatory and not cumulative; and third, the defendant has no other source to obtain the evidence. United States v. Diaz, 176 F.3d 52, 115 (2d Cir.1999). We reject appellant’s claim that the mere fact that many of the government’s witnesses testified under grants of immunity constitutes a “discriminatory use” of the immunity power. See United States v. Todaro, 744 F.2d 5, 10 (2d Cir.1984) (<HOLDING>). We find that the government’s use of its
holding that the number of witnesses immunized by the government without more would not support a finding of discriminatory use holding that material for witnesses need not be produced to defendant where the witnesses were not called as government witnesses at trial holding evidence insufficient to support finding of implied contract holding that criminal defendants are entitled to obtain for impeachment purposes statements made by government witnesses to government agents that relate to the subject matter of the witnesses direct testimony holding that the government had established necessity for wiretaps despite its use of three cooperating witnesses because those witnesses were able to give agents only limited information not including the names of all members of the conspiracy