Although children cannot be transferred without parental permission, the validity of their consent is contestable.
It is a political document, full of contestable characterizations, but it provides some useful specifics to consider.
c.1600, from French contester "dispute, oppose," from Middle French, from Latin contestari (litem) "to call to witness, bring action," from com- "together" (see com-) + testari "to bear witness," from testis "a witness," (see testament). Calling witnesses as the first step in a legal combat. Related: Contestable; contested; contesting.
1640s, from contest (v.).