Is a violation of customary international law an violation of state or federal constitutional law?

Defendant contends the alleged violations of law he has described above also constituted violations of customary international law. As in People v. Hillhouse (2002) 27 Cal.4th 469, 117 Cal.Rptr.2d 45, 40 P.3d 754, we need not consider whether a violation of state or federal constitutional law would also violate international law, "`because defendant has failed to establish the premise that his trial involved violations of state and federal constitutional law. . .."" (Id. at p. 511, 117 Cal.Rptr.2d 45, 40 P.3d 754.) "Moreover, had defendant shown prejudicial error under domestic law, we would have set aside the judgment on that basis without recourse to international law." (Ibid.)