These never get called at the moment, so we have no way of
guaranteeing that any existing implementations are even correct. If
we do decide to start emulating the coin blocker then we will need
to advance the API versions, which will (hopefully) force any
third-party devs to test their coin blocker code before opting in.
Tau
9c2a94eb294ac460ccbd019f5f01f45fffff7759
5d3b9130281102eb36519ddd0a2c6868ff061a3b