What is the test for the consent defense at the Convention of Nations?

the Convention places the burden on the party opposing the return of the child to prove the affirmative defense that the left-behind parent or guardian "consented to or subsequently acquiesced in the removal or retention." Art. 13(a); 22 U.S.C. 9003(e)(2)(B) ; see also Baxter v. Baxter , 423 F.3d 363, 371 (3d Cir. 2005) ("In examining a consent defense, it is important to consider what the petitioner actually contemplated and agreed to in allowing the child to travel outside its home country."). The corollary here is that we presume the left-behind parent or guardian did not consent, and that their lack of consent renders the removal wrongful.